10
unknown(adjective, obscure, mysterious)
6
unidentified(adjective, secret)
5
foreign(adjective, regular, irrelevant)
5
obscure(adjective, unknown)
5
uncharted
5
undiscovered(adjective, familiar)
3
secret(noun, adjective, clandestine, underhand, unrevealed)
3
chartless
2
anonymous(adjective, choice, unknown)
1
faceless
1
mysterious(adjective, secret, concealed)
1
nameless(adjective, unknown, anonymous)
1
unfamiliar(adjective, strange, common, different, unknown)
1
unspecified(adjective, specified)
1
incognito(adjective, disguise)
1
inside(adjective, secret, outside)
1
little-known
1
mystery(noun, understanding, secret, puzzle, abstruseness)
1
occult(adjective, clear, secret, supernatural)
1
private
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APASmart Define. (2015). known thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/known/thesaurus/antonyms
ChicagoSmart Define. 2015. "known thesaurus" https://smartdefine.org/known/thesaurus/antonyms (accessed September 22, 2026).
HarvardSmart Define 2015, known thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/known/thesaurus/antonyms>.
MLASmart Define. "known thesaurus" 14 April 2015. Web. 22 September 2026. <https://smartdefine.org/known/thesaurus/antonyms>