20
ungrateful(adjective, difficult, rude, inconsiderate, grateful)
16
unthankful(adjective, rude, inconsiderate, grateful, churlish)
11
thoughtless(adjective, rude, inconsiderate, unappreciative, ungrateful)
11
unappreciative(adjective, rude, grateful, churlish, ungrateful)
10
unrequited(adjective, unappreciated)
9
unappreciated(adjective, grateful)
9
unpleasant(adjective, pain, rude, disagreeable, lousy)
8
disagreeable(adjective, pain, unpleasant, lousy, unsatisfactory)
8
heedless(adjective, rude, inconsiderate, churlish, unappreciative)
8
unrewarding(adjective, difficult, unsatisfactory, trying, fruitless)
7
distasteful(adjective, pain, disagreeable, lousy, unsatisfactory)
6
fruitless(adjective, difficult, unsatisfactory, trying, unappreciated)
6
unwelcome(adjective, pain, disagreeable, lousy, annoying)
6
useless(adjective, unappreciated)
6
vain(adjective, unappreciated)
5
careless(adjective, rude, inconsiderate, churlish, unappreciative)
5
displeasing(noun, adjective, pain, unpleasant, disagreeable)
5
self-centered(adjective, rude, inconsiderate, churlish, unappreciative)
5
ungracious(adjective, rude, inconsiderate, churlish, unappreciative)
4
bad(adjective, pain, unsatisfactory, fruitless, unfulfilling)
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APASmart Define. (2015). thankless thesaurus. Retrieved September 20, 2026, from https://smartdefine.org/thankless/thesaurus/synonyms
ChicagoSmart Define. 2015. "thankless thesaurus" https://smartdefine.org/thankless/thesaurus/synonyms (accessed September 20, 2026).
HarvardSmart Define 2015, thankless thesaurus, Smart Define, viewed 20 September, 2026, <https://smartdefine.org/thankless/thesaurus/synonyms>.
MLASmart Define. "thankless thesaurus" 14 April 2015. Web. 20 September 2026. <https://smartdefine.org/thankless/thesaurus/synonyms>