Something that is impossible to refuse or reject.

जिसे ठुकराना असंभव हो.

English Usage: His offer was irrecusable; I had to accept it.

Hindi Usage: उसका प्रस्ताव अनिवार्य था; मुझे इसे स्वीकार करना पड़ा।

Not able to be declined or avoided.

जिसे टाला नहीं जा सकता.

English Usage: The meeting was called for an irrecusable reason.

Hindi Usage: बैठक एक अनिवार्य कारण से बुलाई गई थी।