(a.) Of or pertaining to a period before written history begins; as, the prehistoric ages; prehistoric man.

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