Incontrovertible means so certain that it cannot be argued against. Incontrovertible evidence, incontrovertible proof, incontrovertible fact.
It is a very strong claim and is usually overstated, since almost nothing outside mathematics is beyond argument. The word means literally not able to be turned against, from the same root as controversy.
1adjectiveincontrovertibleSo certain that it cannot be argued against.
“The video provided incontrovertible proof that he had been at the scene.”
incontrovertible is a quality.
From in- + controvertible.
Etymology from Wiktionary, CC BY-SA