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 ]

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