1. 古老的;过时的;陈旧的
Archaic means extremely old or extremely old-fashioned.

1. little evolved from or characteristic of an earlier ancestral type

e.g. archaic forms of life
primitive mammals
the okapi is a short-necked primitive cousin of the giraffe

Synonym: primitive

2. so extremely old as seeming to belong to an earlier period

e.g. a ramshackle antediluvian tenement
antediluvian ideas
archaic laws

Synonym: antediluvianantiquated