incontestable.

So firmly established that reasonable challenge cannot overturn it.

Use it for

Words that belong together

• incontestable fact
• incontestable evidence

On the page

The date is incontestable, though its significance remains disputed.

Usage notes

Primary category: analysis / argumentation / evidence. Forms: Comparative more incontestable; superlative most incontestable when comparison is meaningful. Legacy lexical fields mirror sense 1 only. Use numbered sense fields for all meanings. Established modern English lexical item. No separate regional spelling or grammatical inflection entry. Writing functions: evidence, inference, qualification. Commonness: moderately common.