IPA: /ˌɪn.kənˈtɛs.tə.bəl/
KK: /ɪnˈkɒntɛstəbl/
Something that cannot be disputed or argued against; it is accepted as true or certain.
The evidence presented in court was incontestable, leading to a quick verdict.
Incontestable → It is formed from "in-" (meaning not) and "contestare" (meaning to dispute or contest) and the suffix "-able" (meaning capable of). The word means not capable of being disputed or contested.
Think of something that is 'not' ('in-') able to be 'disputed' ('contestare') — that's why incontestable means something that cannot be argued against.