unable to be lost or overturned; not subject to defeat or annulment

अप्रतिवर्तनीय

English Usage: The contract was deemed indefeasibly valid after the final ruling.

Hindi Usage: अनुबंध को अंतिम निर्णय के बाद अप्रतिवर्तनीय रूप से मान्य माना गया।