‖n. pl. [ NL., from Gr. &unr_;, a nettle. ] A group of Cœlenterata, including the Medusæ or jellyfishes, and hydroids; -- so called from the stinging power they possess. Sometimes called sea nettles. [ 1913 Webster ]

{ a. [ L. Achaeus, Achaius; Gr. &unr_;. ] Of or pertaining to Achaia in Greece; also, Grecian. -- n. A native of Achaia; a Greek. [ 1913 Webster ]

{ ‖ ‖ } n. [ althaea, Gr. &unr_;. ] (Bot.) (a) A genus of plants of the Mallow family. It includes the officinal marsh mallow, and the garden hollyhocks. (b) An ornamental shrub (Hibiscus Syriacus) of the Mallow family. [ 1913 Webster ]

‖ n. [ L. ] Same as Apheresis. [ 1913 Webster ]

adj. 1. 1 relating to or formed by or consisting of aphaeresis. [ WordNet 1.5 ]

‖n. pl. [ L., fr. Gr. &unr_; (mostly in pl. &unr_;, Hipp.) an eruption, thrush, fr. &unr_; to set on fire, inflame. ] (Med.) Roundish pearl-colored specks or flakes in the mouth, on the lips, etc., terminating in white sloughs. They are commonly characteristic of thrush. [ 1913 Webster ]

a. [ Gr. 'archai^os ancient, fr. 'archh` beginning. ] Ancient; pertaining to the earliest period in geological history. [ 1913 Webster ]

n. (Geol.) The earliest period in geological period, extending up to the Lower Silurian. It includes an Azoic age, previous to the appearance of life, and an Eozoic age, including the earliest forms of life. [ 1913 Webster ]

☞ This is equivalent to the formerly accepted term Azoic, and to the Eozoic of Dawson. [ 1913 Webster ]

, n. (Microbiol.) A group of single-celled microorganisms including the methanogens and some halophiles and thermoacidophiles, recognized in the 1970's by C. R. Woese and his colleagues as being a distinct group on the basis of RNA sequences, cell walls, and coenzymes differing from those of other microbes. It is believed to be an ancient form of living organism that evolved separately from the eubacteria and blue-green algae. It is classified as a separate kingdom by some taxonomists. See also The Archaebacteria. [ PJC ]

n. [ Gr. 'archai^os ancient + -graphy. ] A description of, or a treatise on, antiquity or antiquities. [ 1913 Webster ]

a. [ Gr. 'archai^os ancient + liqiko`s pertaining to a stone. ] (Archæol.) Of or pertaining to the earliest Stone age; -- applied to a prehistoric period preceding the Paleolithic age. [ 1913 Webster ]

n. An archæologist. [ 1913 Webster ]

{ } Relating to archæology, or antiquities; as, archæological researches. -- Ar`*chæ*o*log"ic*al*ly, adv. [1913 Webster]

n. One versed in archæology; an antiquary. Wright. [ 1913 Webster ]

n. [ Gr. 'archaiologi`a; 'archai^os ancient (fr. 'archh` beginning) + lo`gos discourse, le`gein to speak. ] The science or study of antiquities, esp. prehistoric antiquities, such as the remains of buildings or monuments of an early epoch, inscriptions, implements, and other relics, written manuscripts, etc. [ 1913 Webster ]

‖n. [ Gr. 'archai^os ancient + pte`ryx wing. ] (Paleon.) A fossil bird, of the Jurassic period, remarkable for having a long tapering tail of many vertebræ with feathers along each side, and jaws armed with teeth, with other reptilian characteristics. [ 1913 Webster ]

n. 1. an extinct primitive toothed bird with a long feathered tail and three free clawed digits on each wing. [ WordNet 1.5 ]

n. 1. 1 a subclass of primitive reptilelike fossil birds of the Jurassic or early Cretaceous.
Syn. -- subclass Archaeornithes [ WordNet 1.5 ]

a. [ Gr. 'archai^os ancient + sto`ma mouth. ] (Biol.) Applied to a gastrula when the blastopore does not entirely close up. [ 1913 Webster ]

a. [ Gr. 'archai^os ancient + zw^, on animal. ] (Zool.) Like or belonging to the earliest forms of animal life. [ 1913 Webster ]

2. (Geol.) formed in or belonging to the earlier of two divisions of the Precambrian era. archaeozoic life forms
Syn. -- archeozoic [ WordNet 1.5 ]

n. [ Gr. 'archai^os ancient + zw^, on animal. ] the time from 1.5 billion to 5 billion years ago; the time when the earth's crust formed; a time when only unicellular organisms and the earliest forms of life are present.
Syn. -- Archeozoic, Archeozoic era, Archaeozoic era [ WordNet 1.5 ]

{ ‖‖ n. [ NL., fr. Gr. kako`s bad+ a"i^ma blood.] (Med.) A degenerated or poisoned condition of the blood. [1913 Webster]

‖ ‖/mhw>, n. [ NL., fr. Gr. &unr_; bad + &unr_; blood. ] (Med.) A degenerated or poisoned condition of the blood. -- Ca*chæ"mic, Ca*che"mic a. [ Webster 1913 Suppl. ]

n. a genus of clinid fishes consisting of the pikeblennies.
Syn. -- genus Chaenopsis. [ WordNet 1.5 ]

n. (Greek antiquity) either of two battles in ancient Greece, one in which Philip of Macedon defeated the Athenians and Thebans (338 BC), or another in which Sulla defeated Mithridates (86 BC). [ WordNet 1.5 ]

n.; pl. chaetae /plu>. [ NL., fr. Gr. chai`th hair. ] (Zool.) a stiff chitinous seta or bristle especially of an annelid worm. [ WordNet 1.5 ]

adj. of or relating to chaetae (setae or bristles). [ WordNet 1.5 ]

‖prop. n. [ NL., fr. Gr. chai`th hair. ] (Zool.) A genus of fossil corals, common in the lower Silurian limestones. [ 1913 Webster ]

a. [ Gr. chai`th hair + -ferous. ] (Zool.) Bearing setæ. [ 1913 Webster ]

n. [ Gr. chai`th hair + &unr_;, &unr_;, tooth. ] (Zool.) A marine fish of the family Chætodontidæ. The chætodonts have broad, compressed bodies, and usually bright colors. [ 1913 Webster ]

a. Of or pertaining to the Chætodonts or the family Chætodontidæ. [ 1913 Webster ]

n. a natural family comprising the butterfly fishes.
Syn. -- family Chaetodontidae. [ WordNet 1.5 ]

a. (Zool.) Of or pertaining to the Chætognatha. [ 1913 Webster ]

n. any worm of the Chaetognatha; transparent marine worm with horizontal lateral and caudal fins and a row of movable curved spines at each side of the mouth.
Syn. -- arrowworm. [ WordNet 1.5 ]

‖ n. pl. [ NL., from Gr. &unr_; hair + &unr_; jaw. ] (Zool) a phylum consisting of the arrowworms, a group of small active transparent free-swimming marine worms, of which the genus Sagitta is the type. They have groups of curved spines on each side of the head.
Syn. -- phylum Chaetognatha. [ 1913 Webster + WordNet 1.5 ]

adj. of or pertaining to the Chaetognatha. [ WordNet 1.5 ]

a. (Zool.) Pertaining to the Chætopoda. -- n. One of the Chætopoda. [ 1913 Webster ]

‖n. pl. [ NL., from Gr. &unr_; hair + -poda. ] (Zool.) A very extensive order of Annelida (segmented worms), characterized by the presence of lateral setæ, or spines, on most or all of the segments. They are divided into two principal groups: Oligochæta, including the earthworms and allied forms, and Polychæta, including most of the marine species. [ 1913 Webster ]

n. [ Gr. &unr_; hair + &unr_; arrangement. ] (Zool.) The arrangement of bristles on an insect. [ 1913 Webster ]

‖n. pl. [ NL., from Gr. &unr_; the wild goose + morfh` form. ] (Zool.) An order of birds, including the swans, ducks, geese, flamingoes and screamers. [ 1913 Webster ]

n. [ Gr. &unr_;, &unr_;, bile + &unr_; dusky. ] (Physiol.) See Bilirubin. [ 1913 Webster ]

a. [ NL. coryphaena + -oid. ] (Zool.) Belonging to, or like, the genus Coryphæna. See Dolphin. [ 1913 Webster ]

a. (Anat.) Pertaining to, or in relation with, both dermal and hæmal structures; as, the dermohæmal spines or ventral fin rays of fishes. [ 1913 Webster ]

‖prop. n. [ NL., fr. I gryphus, or qryps, gen. gryphis, a griffin. ] (Zool.) A genus of cretaceous fossil shells allied to the oyster. [ 1913 Webster ]

[ L. hæcce this. ] (Logic) Literally, this-ness. A scholastic term to express individuality or singleness; as, this book. [ 1913 Webster ]

n. [ Haema- + Gr. chrw^ma color. ] (Physiol. Chem.) Hematin. [ 1913 Webster ]

n. [ Haema- + Gr. ky`anos a dark blue substance. ] (Physiol. Chem.) A substance found in the blood of the octopus, which gives to it its blue color. [ 1913 Webster ]

☞ When deprived of oxygen it is colorless, but becomes quickly blue in contact with oxygen, and is then generally called oxyhaemacyanin. A similar blue coloring matter has been detected in small quantity in the blood of other animals and in the bile. [ 1913 Webster ]

n. [ Haema + Gr. ky`tos a hollow vessel + -meter. ] (Physiol.) An apparatus for determining the number of corpuscles in a given quantity of blood. [ 1913 Webster ]

adv. [ Haema- + L. ad toward. ] (Anat.) Toward the haemal side; on the haemal side of; -- opposed to neurad. [ 1913 Webster ]

n. [ Haema- + Gr. dro`mos course + -graph. ] (Physiol.) An instrument for registering the velocity of the blood.