26
ancient(adjective, original, old, past, primitive)
17
old(adjective, original, past, primitive, early)
15
antediluvian(adjective, antiquated, before, oldness)
13
primeval(adjective, original, fixed, primitive, early)
12
antique(adjective, old, traditional, early, antiquated)
12
archaic(adjective, old, early, antique, antiquated)
12
primitive(adjective, original, old, past, ancient)
11
primordial(adjective, original, primitive, early, antique)
10
antiquated(adjective, old, early, antique, before)
10
early(adjective, before)
8
prehistorical
7
earliest(adjective, before)
6
old-fashioned(adjective, old, traditional, early, antique)
5
primal(adjective, primary, primeval)
4
Noachian
4
aboriginal(adjective, oldness)
4
fossil(adjective, oldness)
4
obsolete(noun, adjective, old, traditional, early)
4
olden(adjective, before)
4
superannuated
10 years ago|3.8k views|share |citing 
APASmart Define. (2016). prehistoric thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/prehistoric/thesaurus/synonyms
ChicagoSmart Define. 2016. "prehistoric thesaurus" https://smartdefine.org/prehistoric/thesaurus/synonyms (accessed September 21, 2026).
HarvardSmart Define 2016, prehistoric thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/prehistoric/thesaurus/synonyms>.
MLASmart Define. "prehistoric thesaurus" 29 February 2016. Web. 21 September 2026. <https://smartdefine.org/prehistoric/thesaurus/synonyms>