Synonyms of unforgivable in English:

unforgivable


See definition of unforgivable

adjective

1‘he had committed the unforgivable sin—he had informed on his friends’

SYNONYMS
inexcusable, unpardonable, unjustifiable, indefensible, reprehensible, outrageous, deplorable, insupportable, despicable, contemptible, disgraceful, shameful
inexpiable, irremissible, unwarrantable, condemnable
mortal, deadly
ANTONYMS

forgivable, unserious, venial