1.  archaic(s = adj.all) antediluvian, antiquated - so extremely old as seeming to belong to an earlier period; "a ramshackle antediluvian tenement"; "antediluvian ideas"; "archaic laws"

2.  archaic(s = adj.all) primitive - little evolved from or characteristic of an earlier ancestral type; "archaic forms of life"; "primitive mammals"; "the okapi is a short-necked primitive cousin of the giraffe"

   Of or characterized by antiquity or archaism; antiquated; obsolescent. [1913 Webster]

archaic, adj.
1 a antiquated. b (of a word etc.) no longer in ordinary use, though retained for special purposes.
2 primitive.
3 of an early period of art or culture, esp. the 7th-6th c. BC in Greece.

Derivative:
archaically adv.

Etymology:
F archa{iuml}que f. Gk arkha{iuml}kos (as ARCHAEAN)

N  neology, neologism, newfangled expression, nonce expression, back-formation, caconym, barbarism, archaism, black letter, monkish Latin, corruption, missaying, malapropism, antiphrasis, pun, paranomasia, play upon words, word play, double- entendre, palindrome, paragram, anagram, clinch, abuse of language, abuse of terms, dialect, brogue, idiom, accent, patois, provincialism, regionalism, localism, broken English, lingua franca, Anglicism, Briticism, Gallicism, Scotticism, Hibernicism, Americanism, Gypsy lingo, Romany, pidgin, pidgin English, pigeon English, Volapuk, Chinook, Esperanto, Hindustani, kitchen Kaffir, dog Latin, macaronics, gibberish, confusion of tongues, Babel, babu English, chi-chi, figure of speech, byword, colloquialism, informal speech, informal language, substandard language, vernacular, vulgar language, obscene language, obscenity, vulgarity, jargon, technical terms, technicality, lingo, slang, cant, argot, St. Gile's Greek, thieves' Latin, peddler's French, flash tongue, Billingsgate, Wall Street slang, pseudology, pseudonym, Mr, So-and-so, wha d'ye call 'em, whatchacallim, what's his name, thingummy, thingumbob, je ne sais quoi, neologist, coiner of words, neologic, neological, archaic, obsolete, colloquial, Anglice.

N  oldness, age, antiquity, cobwebs of antiquity, maturity, decline, decay, senility, seniority, eldership, primogeniture, archaism, thing of the past, relic of the past, megatherium, Sanskrit, tradition, prescription, custom, immemorial usage, common law, old, ancient, antique, of long standing, time-honored, venerable, elder, eldest, firstborn, prime, primitive, primeval, primigenous, paleolontological, paleontologic, paleoanthropological, paleoanthropic, paleolithic, primordial, primordinate, aboriginal, diluvian, antediluvian, protohistoric, prehistoric, antebellum, colonial, precolumbian, patriarchal, preadamite, paleocrystic, fossil, paleozoolical, paleozoic, preglacial, antemundane, archaic, classic, medieval, Pre-Raphaelite, ancestral, black-letter, immemorial, traditional, prescriptive, customary, whereof the memory of man runneth not to the contr, inveterate, rooted, antiquated, of other times, rococo, of the old school, after-age, obsolete, out of date, out of fashion, out of it, stale, old-fashioned, behind the age, old-world, exploded, gone out, gone by, passe, run out, senile, time worn, crumbling, secondhand, old as the hills, old as Methuselah, old as Adam, old as history, Archeozoic, Proterozoic, Paleozoic, Mesozoic, Cenozoic, Precambrian, Cambrian, Ordovician, Silurian, Devonian, Mississippian, Pennsylvanian, Permian, Triassic, Jurassic, Cretaceous, Tertiary, Paleogene, Neocene, Quaternary, Paleocene, Eocene, Oligocene, Miocene, Pliocene, Pleistocene, Recent, since the world was made, since the year one, since the days of Methuselah, vetera extollimus recentium incuriosi.