Irremediable :: Irremediable (a.) Not to be remedied, corrected, or redressed; incurable; as, an irremediable disease or evil..
Irremediably :: Irremediably (adv.) In a manner, or to a degree, that precludes remedy, cure, or correction..
Remediable :: Remediable (a.) Capable of being remedied or cured.