6
old-time(adjective, dull, new, last, original)
5
outworn(adjective, odd, old, primitive, unfashionable)
5
old hat(expression, adjective, idiom, plain, square)
5
oldfangled(adjective, last, original, odd, old)
5
out of date(expression, idiom)
5
unfashionable(adjective, plain, last, original, odd)
4
behind the times(expression, adjective, idiom, odd, current)
4
bygone(adjective, plain, new, last, original)
4
disused
4
musty(adjective, odd, old, primitive, unfashionable)
4
old fashioned(expression, idiom)
4
out(adjective, adverb, odd, old, primitive)
3
anachronistic
3
belated(adjective, late)
3
dead(adjective, odd, old, primitive, unfashionable)
3
expired(adjective, feature, characteristic, trait)
3
late(adjective, last, original, late, venerable)
3
stale(adjective, last, original, tired, venerable)
3
time
3
up(preposition, expired)
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APASmart Define. (2015). outdated thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/outdated/thesaurus/synonyms
ChicagoSmart Define. 2015. "outdated thesaurus" https://smartdefine.org/outdated/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2015, outdated thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/outdated/thesaurus/synonyms>.
MLASmart Define. "outdated thesaurus" 10 April 2015. Web. 22 September 2026. <https://smartdefine.org/outdated/thesaurus/synonyms>