{ a. [ L. Achaeus, Achaius; Gr. &unr_;. ] Of or pertaining to Achaia in Greece; also, Grecian. -- n. A native of Achaia; a Greek. [ 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. [ NL., fr. Gr. leyko`s white + a"i^ma blood.] (Med.) See Leukemia. [Written also leukemia, leukaemia,a nd leucemia.]
-- Leu*chæm"ic a. [ Written also leukemic and leukaemic. ] [ 1913 Webster ]

n. A genus of wildflowers of Western North America.
Syn. -- genus Machaeranthera. [ WordNet 1.5 ]

{ ‖‖ } n. [ NL., fr. Gr. ma`chaira dagger + 'odoy`s tooth. ] (Paleon.) A genus of extinct mammals allied to the cats, and having in the upper jaw canine teeth of remarkable size and strength; -- hence called saber-toothed tigers. [ 1913 Webster ]

{ , a. Of or pertaining to the Manichaeans. [ 1913 Webster ]

{ , n. [ LL. Manichaeus: cf. F. manichéen. ] A believer in the doctrines of Manes, a Persian of the third century A. D., who taught a dualism in which Light is regarded as the source of Good, and Darkness as the source of Evil. [ 1913 Webster ]

The Manichaeans stand as representatives of dualism pushed to its utmost development. Tylor. [ 1913 Webster ]

{ , n. [ Cf. F. manichéisme. ] The doctrines taught, or system of principles maintained, by the Manichaeans. [ 1913 Webster ]

n. [ Michael + mass religious service; OE. Mighelmesse. ] The feast of the archangel Michael, a church festival, celebrated on the 29th of September. Hence, colloquially, autumn. [ 1913 Webster ]

Michaelmas daisy. (Bot.) See under Daisy. [ 1913 Webster ]

prop. n. pl. [ NL., fr. Gr. 'oli`gos little, pl., few + &unr_; hair. ] (Zool.) An order of Annelida which includes the earthworms and related species, including some small freshwater species. [ 1913 Webster +PJC ]

n. Any of an order of hermaphroditic terrestrial and aquatic annelids (including the earthworms) having bristles borne singly along the length of the body; a member of the Oligochaeta.
Syn. -- oligochaete worm. [ WordNet 1.5 ]

n. Of or pertaining to the Oligochaeta. [ archaic ]
Syn. -- Oligochete. [ PJC ]

n. [ See Perichaetium. ] (Bot.) The leafy involucre surrounding the fruit stalk of mosses; perichaetium; perichete. [ 1913 Webster ]

a. (Bot.) Of or pertaining to the perichæth. [ 1913 Webster ]

‖n.; pl. Perichaetia [ NL., fr. Gr. about + &unr_; flowing hair, foliage. ] (Bot.) Same as Perichæth. [ 1913 Webster ]

a. [ See Perichætium. ] (Zool.) Surrounded by setæ; -- said of certain earthworms (genus Perichætus). [ 1913 Webster ]

‖n. pl. [ NL., from Gr. poly`s many + &unr_; hair. ] (Zool.) One of the two principal groups of Chætopoda. It includes those that have prominent parapodia and fascicles of setæ. See Illust. under Parapodia. [ 1913 Webster ]

{ ‖‖ } n. [ L. spira a coil + Gr. &unr_;&unr_;&unr_; hair. ] (Biol.) A genus of Spirobacteria similar to Spirillum, but distinguished by its motility. One species, the Spirochaete Obermeyeri, is supposed to be the cause of relapsing fever. [ 1913 Webster ]