IPA: //ʌnˈstɒpəblɪ//
KK: /ʌnˈstɑːpəbli/
In a way that cannot be stopped or prevented.
The team moved forward unstoppably, determined to win the championship.
Unstoppably → It is formed from "un-" (meaning not) and "stoppable" (from the root "stop" which comes from Old English "stoppian", meaning to close or block). The suffix "-ly" (meaning in a manner) indicates the manner of being not stoppable. Therefore, "unstoppably" means in a manner that cannot be stopped.
Think of 'not' ('un-') being able to 'block' ('stop') something — that's why 'unstoppably' means something that cannot be stopped.