unwiderruflich
irrevocable
No longer able to be undone or revoked; final and definitive.
Mit seiner Unterschrift ist der Vertrag unwiderruflich gültig geworden.
With his signature, the contract became irrevocably valid.

irrevocable
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irrevocable
No longer able to be undone or revoked; final and definitive.
Mit seiner Unterschrift ist der Vertrag unwiderruflich gültig geworden.
With his signature, the contract became irrevocably valid.

The word consists of 'un-' and 'widerruflich' (revocable). 'Widerruflich' is derived from the verb 'widerrufen' (to revoke), which means 'to take back' or 'to cancel'. So 'unwiderruflich' (irrevocable) describes a state that can no longer be taken back.
Seine Kündigung ist unwiderruflich.
His resignation is irrevocable.
This word is often connected with decisions, consequences, or the end of something. Typical phrases are 'eine unwiderrufliche Entscheidung' (an irrevocable decision), 'unwiderruflich verloren' (irrevocably lost), or 'unwiderruflich vorbei' (irrevocably over).
Die Zeit unserer Kindheit ist unwiderruflich vorbei.
The time of our childhood is irrevocably over.
'Unwiderruflich' (irrevocable) is a formal word that is often used in legal and administrative language. It emphasizes the finality and binding nature of an action or state.
Das Urteil des Gerichts ist unwiderruflich.
The court's judgment is irrevocable.
definitely / definitive
'definitiv' and 'unwiderruflich' can both mean that something is final. 'Definitiv' is more general: a decision, a result, or a date is fixed and is not meant to be changed anymore. 'Unwiderruflich' is stronger and more specific when something can no longer be taken back or undone. The word often fits with terminations, contracts, decisions, or consequences. Memory tip: everything that is 'unwiderruflich' is 'definitiv', but not everything that is 'definitiv' is automatically 'unwiderruflich'.

Mit der Unterschrift ist der Vertrag unwiderruflich gültig.
With the signature, the contract is irrevocably valid.
Der Termin für die Prüfung ist jetzt definitiv.
The date for the exam is now definitive.