Etymology From Middle English unavoidable, equivalent to un- + avoidable.
1
Impossible to avoid; bound to happen.
an unavoidable urge
2
Law Not voidable; incapable of being made null or void.
A confirmation is allied to a release, being a conveyance of an estate or right in esse whereby a voidable estate is made unavoidable1765–1769, William Blackstone, Commentaries on the Laws of England, (please specify |book=I to IV), Oxford, Oxfordshire: […] Clarendon Press, →OCLC:
Etymology From Middle English unavoidable, equivalent to un- + avoidable.
1
Something that cannot be avoided.
Forty years before, I had thought this odour one of the necessities of life — one of the unavoidables at least[…]1825, The London magazine, volume 12, page 490: