IRREMISSIBLE Meaning of IRREMISSIBLE in English adj. 1 unpardonable. 2 unalterably obligatory. irremissibly adv.[ ME f. OF irremissible or eccl.L irremissibilis (as IN-(1), REMISSIBLE) ] Concise Oxford English dictionary. Краткий оксфордский словарь английского языка. 2012