unimpeachable[adjective]Synonyms: decent, acceptable, adequate, all right, common, satisfactory, sufficient, tolerable, unexceptionable, unexceptional
[TahlilGaran] English Synonym Dictionary ▲
un‧im‧peach‧a‧ble /ˌʌnɪmˈpiːtʃəb
əl◂/
adjective formal so good or definite that criticism or doubt is impossible:
unimpeachable morals—unimpeachably adverb [TahlilGaran] Dictionary of Contemporary English ▲