17
portentous(adjective, importance, valuable, main, notable)
16
considerable(adjective, importance, big, heavy, important)
16
influential(adjective, importance, important, powerful, valuable)
15
impressive(adjective, bad, strong, great, excellent)
15
outstanding(adjective, excellent, extraordinary, superior, importance)
15
solemn(adjective, importance, valuable, main, notable)
14
historic(adjective, importance, important, main, extremely significant)
14
unforgettable(adjective, importance)
13
noteworthy(adjective, great, solid, extraordinary, big)
12
grand(adjective, importance, valuable, main, notable)
12
meaningful(adjective, good, clear, strong, great)
11
eventful(adjective, bad, great, excellent, extraordinary)
11
responsible(adjective, importance, valuable, duty, reliable)
11
signal(adjective, great, solid, extraordinary, importance)
10
big-league(adjective, importance, valuable, main, notable)
10
decisive(adjective, great, extraordinary, big, important)
10
earnest(adjective, importance, important, valuable, main)
10
key(adjective, importance, valuable, main, notable)
9
bigwig(adjective, importance, valuable, main, notable)
9
chief(adjective, bad, great, excellent, superior)
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APASmart Define. (2016). momentous thesaurus. Retrieved September 29, 2026, from https://smartdefine.org/momentous/thesaurus/synonyms
ChicagoSmart Define. 2016. "momentous thesaurus" https://smartdefine.org/momentous/thesaurus/synonyms (accessed September 29, 2026).
HarvardSmart Define 2016, momentous thesaurus, Smart Define, viewed 29 September, 2026, <https://smartdefine.org/momentous/thesaurus/synonyms>.
MLASmart Define. "momentous thesaurus" 1 April 2016. Web. 29 September 2026. <https://smartdefine.org/momentous/thesaurus/synonyms>