| Prehistoric (a.) Of or pertaining to a period before written history begins; as, the prehistoric ages; prehistoric man. Thesaurus Entries aboriginal, ancestral, ancient, antediluvian, antepatriarchal, antiquated, atavistic, autochthonous, earliest, early, erstwhile, fore, former, fossil, humanoid, immemorial, late, old, old-fashioned, olden, once, onetime, passe, past, patriarchal, preadamite, preglacial, prehuman, previous, primal, prime, primeval, primitive, primogenial, primoprimitive, primordial, prior, pristine, protohistoric, protohuman, quondam, recent, sometime, then |