Synonyms|396Antonyms|89|Broader|6Narrower|5Related|200
4
then(adverb, time)
3
ages ago(expression, adjective, adverb, late, old)
3
ancient(adjective, late, old, past, previous)
3
at once(expression, idiom)
3
early(adjective, last, original, late, old)
3
in times past(expression, adjective, idiom, adverb, past)
3
now and then(expression, time, moment, rare, frequency)
3
olden(adjective, original, late, old, past)
3
one day(expression, idiom, time)
3
one fine morning(expression, idiom, time)
3
periodically
3
right away(noun, verb, phrasal verb)
3
simultaneously
3
sporadically
2
aforetime(adverb, earlier, then, precede, before)
2
ago
2
ahead
2
anyway
2
at a stroke(expression, idiom)
2
at any time(expression, idiom, conjunction)
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APASmart Define. (2016). once thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/once/thesaurus/synonyms
ChicagoSmart Define. 2016. "once thesaurus" https://smartdefine.org/once/thesaurus/synonyms (accessed September 22, 2026).
HarvardSmart Define 2016, once thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/once/thesaurus/synonyms>.
MLASmart Define. "once thesaurus" 30 March 2016. Web. 22 September 2026. <https://smartdefine.org/once/thesaurus/synonyms>