形容詞 archaic:

1. so extremely old as seeming to belong to an earlier period
   同義詞：antediluvian, antiquated
2. little evolved from or characteristic of an earlier ancestral type
   同義詞：primitive

1. An archaic word, phrase, idiom, or other expression.
   古詞，古語(yǔ)古詞、古短語(yǔ)、古習(xí)語(yǔ)或其它表達(dá)(形式)

ar.cha.ic

adj.Abbr. arch.（形容詞）縮寫 arch.
Of, relating to, or characteristic of a much earlier, often more primitive period:
創(chuàng)始期的：一種很早的，常為更原始時(shí)期的，或與之有關(guān)的，或有其特征的：
例句：
an archaic bronze statuette.
一種相當(dāng)古老的青銅小雕像

No longer current or applicable; antiquated:
過(guò)時(shí)的，陳舊的：不再流行或使用的；過(guò)時(shí)的：
例句：
archaic laws.See Synonyms at old
已不使用的法律參見(jiàn) old

Of, relating to, or characteristic of words and language that were once common but are now used chiefly to suggest an earlier style or period.
古體的，已不通用的：曾經(jīng)通用而現(xiàn)在不再使用主要指早期風(fēng)格或時(shí)代的單詞或語(yǔ)言的，與之有關(guān)的或具有其特征的

來(lái)源：
Greek arkhaikos [old-fashioned]
希臘語(yǔ) arkhaikos [過(guò)時(shí)]
from arkhaios [ancient]
源自 arkhaios [古代的]
from arkhô [beginning]
源自 arkhô [開始]
from arkhein [to begin]
源自 arkhein [開始]

【引伸】
archa.ically
adv.（副詞）