2
regressing(verb, deteriorating)
2
regression(noun, drop, decline, fall, deterioration)
2
retrogression(noun, decline, deterioration)
2
reversion(noun, decline, deterioration)
2
ripe(adjective, age)
2
senescent(noun, decrease, stale, ebb, fading)
2
shrinking(adjective, lessening, declining, lowering, falling)
2
stunted
2
subsidence(noun, drop, cut, decline, decrease)
2
twilight
2
vanishing(adjective, lessening, dying, fading, deteriorating)
1
abate
1
abatement(noun, drop, cut, decline, fall)
1
aged
1
ancient
1
anile
1
antiquated
1
astringent
1
at rest
1
backflow(noun, drop, decrease, retreat, wane)
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APASmart Define. (2015). waning thesaurus. Retrieved September 23, 2026, from https://smartdefine.org/waning/thesaurus/synonyms
ChicagoSmart Define. 2015. "waning thesaurus" https://smartdefine.org/waning/thesaurus/synonyms (accessed September 23, 2026).
HarvardSmart Define 2015, waning thesaurus, Smart Define, viewed 23 September, 2026, <https://smartdefine.org/waning/thesaurus/synonyms>.
MLASmart Define. "waning thesaurus" 13 April 2015. Web. 23 September 2026. <https://smartdefine.org/waning/thesaurus/synonyms>