n. [ Acetyl + amide. ] (Chem.) A white crystalline solid, from ammonia by replacement of an equivalent of hydrogen by acetyl. [ 1913 Webster ]

n. [ Alkali + amide. ] (Chem.) One of a series of compounds that may be regarded as ammonia in which a part of the hydrogen has been replaced by basic, and another part by acid, atoms or radicals. [ 1913 Webster ]

prep. See Amidst. [ 1913 Webster ]

{ } prep. [ OE. amidde, amiddes, on midden, AS. on middan, in the middle, fr. midde the middle. The s is an adverbial ending, originally marking the genitive; the t is a later addition, as in whilst, amongst, alongst. See Mid. ] In the midst or middle of; surrounded or encompassed by; among. “This fair tree amidst the garden.” “Unseen amid the throng.” “Amidst thick clouds.” Milton. “Amidst acclamations.” “Amidst the splendor and festivity of a court.” Macaulay. [ 1913 Webster ]

But rather famish them amid their plenty. Shak. [ 1913 Webster ]

Syn. -- Amidst, Among. These words differ to some extent from each other, as will be seen from their etymology. Amidst denotes in the midst or middle of, and hence surrounded by; as, this work was written amidst many interruptions. Among denotes a mingling or intermixing with distinct or separable objects; as, “He fell among thieves.” “Blessed art thou among women.” Hence, we say, among the moderns, among the ancients, among the thickest of trees, among these considerations, among the reasons I have to offer. Amid and amidst are commonly used when the idea of separate or distinguishable objects is not prominent. Hence, we say, they kept on amidst the storm, amidst the gloom, he was sinking amidst the waves, he persevered amidst many difficulties; in none of which cases could among be used. In like manner, Milton speaks of Abdiel, -- The seraph Abdiel, faithful found;
Among the faithless faithful only he, [ 1913 Webster ] because he was then considered as one of the angels. But when the poet adds, -- From amidst them forth he passed, [ 1913 Webster ] we have rather the idea of the angels as a collective body. Those squalid cabins and uncleared woods amidst which he was born. Macaulay. [ 1913 Webster ]

n. [ Ammonia + -ide. ] (Chem.) A compound formed by the union of amidogen with an acid element or radical. It may also be regarded as ammonia in which one or more hydrogen atoms have been replaced by an acid atom or radical. [ 1913 Webster ]

Acid amide, a neutral compound formed by the substitution of the amido group for hydroxyl in an acid. [ 1913 Webster ]

n. [ Cf. F. amidine, fr. amido&unr_; starch, fr. L. amylum, Gr. &unr_; fine meal, neut. of &unr_; not ground at the mill, -- hence, of the finest meal; 'a priv. + &unr_;, &unr_;, mill. See Meal. ] (Chem.) Start modified by heat so as to become a transparent mass, like horn. It is soluble in cold water. [ 1913 Webster ]

a. [ From Amide. ] (Chem.) Containing, or derived from, amidogen. [ 1913 Webster ]

Amido acid, an acid in which a portion of the nonacid hydrogen has been replaced by the amido group. The amido acids are both basic and acid. --
Amido group, amidogen, NH2. [ 1913 Webster ]

n. [ Amide + -gen. ] (Chem.) A compound radical, NH2, not yet obtained in a separate state, which may be regarded as ammonia from the molecule of which one of its hydrogen atoms has been removed; -- called also the amido group, and in composition represented by the form amido. [ 1913 Webster ]

n. [ Amide + -ol as in alcohol. ] (Photog. & Chem.) A salt of a diamino phenol, C6H3(OH)(NH2)2, used as a developer. [ Webster 1913 Suppl. ]

adv. (Naut.) In the middle of a ship, with regard to her length, and sometimes also her breadth. Totten. [ 1913 Webster ]

n. 1. 1 a natural family comprising the wood swallows.
Syn. -- family Artamidae. [ WordNet 1.5 ]

n. [ Benzoin + amide. ] (Chem.) A transparent crystalline substance, C6H5.CO.NH2, obtained by the action of ammonia upon chloride of benzoyl, as also by several other reactions with benzoyl compounds. [ 1913 Webster ]

a. [ Pref. bi- + pyramidal. ] Consisting of two pyramids placed base to base; having a pyramid at each of the extremities of a prism, as in quartz crystals. [ 1913 Webster ]

n. [ Carbonyl + amide. ] (Chem.) The technical name for urea. [ 1913 Webster ]

n. a natural family of cranelike South American wading birds.
Syn. -- family Cariamidae. [ WordNet 1.5 ]

n. [ Chloral + amide. ] (Chem.) A compound of chloral and formic amide used to produce sleep. [ 1913 Webster ]

n. [ Pref. di- + amide. ] (Chem.) Any compound containing two amido groups united with one or more acid or negative radicals, -- as distinguished from a diamine. Cf. Amido acid, under Amido, and Acid amide, under Amide. [ 1913 Webster ]

a. (Chem.) A prefix or combining form of Diamine. [ Also used adjectively. ] [ 1913 Webster ]

n. [ Hydr- + -amide. ] (Chem.) One of a group of crystalline bodies produced by the action of ammonia on certain aldehydes. [ 1913 Webster ]

n. [ Lactic + amide. ] (Chem.) An acid amide derived from lactic acid, and obtained as a white crystalline substance having a neutral reaction. It is metameric with alanine. [ 1913 Webster ]

n. [ Macro- + pyramid. ] (Crystallog.) See Macroprism. [ 1913 Webster ]

n. [ Malic + amide. ] (Chem.) The acid amide derived from malic acid, as a white crystalline substance metameric with asparagine. [ 1913 Webster ]

n. [ Mon- + amide. ] (Chem.) An amido compound with only one amido group; a monoamide. [ 1913 Webster ]

n. [ Mucic + amide. ] (Chem.) The acid amide of mucic acid, obtained as a white crystalline substance. [ 1913 Webster ]

n. The amide of niacin (nicotinic acid), called also nicotinamide. It was at one time called vitamin B₃, and can function to relieve nicotinic acid deficiency. Chemical formula C6H6N2O, chemically it is 3-pyridinecarboxamide.
Syn. -- nicotinic acid amide, nicotinamide. [ PJC ]

n. [ Oxaluric + amide. ] (Chem.) Same as Oxalan. [ 1913 Webster ]

n, [ Oxalic + amide. ] (Chem.) A white crystalline neutral substance (C2O2(NH2)2) obtained by treating ethyl oxalate with ammonia. It is the acid amide of oxalic acid. Formerly called also oxalamide. [ 1913 Webster ]

n. [ Oxygen + amido + -ine. ] (Chem.) One of a series of bases containing the amido and the isonitroso groups united to the same carbon atom. [ 1913 Webster ]

n. [ Oxanilic + amide. ] (Chem.) A white crystalline nitrogenous substance, obtained indirectly by the action of cyanogen on aniline, and regarded as an anilide of oxamic acid; -- called also phenyl oxamide. [ 1913 Webster ]

n. A white crystalline compound used as an analgesic and also as an antipyretic.
Syn. -- acetanilide, acetanilid. [ WordNet 1.5 ]

n. [ Potassium + amide. ] (Chem.) A yellowish brown substance obtained by heating potassium in ammonia. [ 1913 Webster ]

n. [ L. pyramis, -idis, fr. Gr. &unr_;, &unr_;, of Egyptian origin: cf. F. pyramide. ] [ 1913 Webster ]

1. A solid body standing on a triangular, square, or polygonal base, and terminating in a point at the top; especially, a structure or edifice of this shape. [ 1913 Webster ]

2. (Geom.) A solid figure contained by a plane rectilineal figure as base and several triangles which have a common vertex and whose bases are sides of the base. [ 1913 Webster ]

3. pl. (Billiards) The game of pool in which the balls are placed in the form of a triangle at spot. [ Eng. ] [ 1913 Webster ]

4. (Finance) a fraudulent investment scheme in which the manager promises high profits, but instead of investing the money in a genuine profit-making activity, uses the money from later investors to pay the profits to earlier investors; -- also called pyramid scheme or pyramid operation. This process inevitably collapses when insufficient new investors are available, leaving the later investors with total or near-total losses of their investments. The managers usually blame government regulations or interference for the collapse of the scheme, rather than admit fraud. [ PJC ]

Altitude of a pyramid (Geom.), the perpendicular distance from the vertex to the plane of the base. --
Axis of a pyramid (Geom.), a straight line drawn from the vertex to the center of the base. --
Earth pyramid. (Geol.) See Earth pillars, under Earth. --
Right pyramid (Geom.) a pyramid whose axis is perpendicular to the base. [ 1913 Webster ]

v. i. (Speculation) To enlarge one's holding or interest in a series of operations on a continued rise or decline by using the profits to buy or sell additional amounts on a margin, as where one buys on a 10% margin 100 shares of stock quoted at 100, holds it till it rises to 105, and then uses the paper profit to buy 50 shares more, etc. The series of operations constitutes a pyramid. A similar process of reinvesting gains or winnings (as of a gamble), but not involving operation on margin, is called a parlay. [ Webster 1913 Suppl. +PJC ]

v. t. (Speculation) To use, or to deal in, in a pyramiding transaction. See Pyramid, v. i. [ Webster 1913 Suppl. ]

a. [ Cf. F. pyramidal. ] [ 1913 Webster ]

1. Of or pertaining to a pyramid; in the form of a a pyramid; pyramidical; as, pyramidal cleavage. [ 1913 Webster ]

The mystic obelisks stand up
Triangular, pyramidal. Mrs. Browning. [ 1913 Webster ]

2. (Crystallog.) Same as Tetragonal. [ 1913 Webster ]

Pyramidal numbers (Math.), certain series of figurate numbers expressing the number of balls or points that may be arranged in the form of pyramids. Thus 1, 4, 10, 20, 35, etc., are triangular pyramidal numbers; and 1, 5, 14, 30, 55, etc., are square pyramidal numbers. [ 1913 Webster ]

n. (Anat.) One of the carpal bones. See Cuneiform, n., 2 (b). [ 1913 Webster ]

adv. Like a pyramid. [ 1913 Webster ]

{ } a. Of or pertaining to a pyramid; having the form of a pyramid; pyramidal. “ A pyramidical rock.” Goldsmith. “Gold in pyramidic plenty piled.” Shenstone. -- Pyr`a*mid"ic*al*ly, adv. Pyr`a*mild"ic*al*ness, n. [ 1913 Webster ]

‖n.; pl. Pyramidia [ NL., from L. pyramis. See Pyramid. ] The small pyramid which crowns or completes an obelisk. [ 1913 Webster ]

n. [ Gr. &unr_;, &unr_;, pyramid + -id: cf. F. pyramidoïde. ] A solid resembling a pyramid; -- called also pyramoid. Barlow. [ 1913 Webster ]

n. (Chem.) A greenish or reddish crystalline substance, NaNH2, obtained by passing ammonia over heated sodium. [ 1913 Webster ]

n. (Chem.) Any one of a series of amido compounds obtained by treating sulphuryl chloride with various amines. [ 1913 Webster ]

n. [ Tarto- + amide. ] (Chem.) An acid amide derivative of tartaric acid, obtained as a white crystalline substance. [ 1913 Webster ]

‖n. pl. [ NL. ] (Zool.) A division of struthious birds, including the tinamous. [ 1913 Webster ]

n. [ tri- + amine. ] (Chem.) An amide containing three amido groups. [ 1913 Webster ]

n. [ Valeric + amide. ] (Chem.) The acid amide derivative of valeric acid, obtained as a white crystalline substance. [ 1913 Webster ]

n. [ Xanthic + amide. ] (Chem.) An amido derivative of xanthic acid obtained as a white crystalline substance, C2H5O.CS.NH2; -- called also xanthogen amide. [ 1913 Webster ]

n. [ Xylic + amide. ] (Chem.) An acid amide derivative of xylic acid, obtained as a white crystalline substance. [ 1913 Webster ]