IPA: //ʌnˈmɪs.teɪ.kə.bəl//
KK: /ʌnˈmɪsˌteɪkəbl/
Something that is clear and cannot be confused with anything else; it is obvious and easy to recognize.
The unmistakable sound of the train could be heard from miles away.
Unmistakable → It is formed from "un-" (meaning not), "mistake" (from Old French *mistake*, meaning to take wrongly), and "-able" (meaning capable of). The word "unmistakable" means not capable of being taken wrongly or clearly recognizable.
Think of something that is 'not' ('un-') able to be 'taken wrongly' ('mistake') — that's why unmistakable means something that is clear and obvious.