Adjective: irremissible ,i-ri'mi-su-bul
- Not admitting of pardon
"irremissible behaviour";
- unpardonable
- Morally or legally constraining or binding
"attendance is irremissible";
- obligatory
See also: bounden [archaic], compulsory, de rigueur, deadly, imposed, incumbent on, indispensable, inexcusable, inexpiable, mandatory, mortal, necessary, prerequisite, required, unforgivable