Synonyms of thankless in English:

thankless


See definition of thankless

adjective

1‘a thankless task’

SYNONYMS
unappreciated, unrecognized, unrewarded, unacknowledged
unenviable, difficult, unpleasant, unrewarding, unprofitable, profitless, useless, fruitless, vain, futile
archaic bootless
ANTONYMS

rewarding, worthwhile

2‘her thankless children’

SYNONYMS
ungrateful, unappreciative, unthankful
ANTONYMS

grateful