irreprehensible (adj.)

"blameless," late 14c., from Late Latin irreprehensibilis, from Latin irreprehensus "blameless, without blame," from assimilated form of in- "not, opposite of" (see in- (1)) + reprehensibilis, from past participle stem of Latin reprehendere "to blame, censure, rebuke; seize, restrain" (see reprehend).