IPA: /ˌoʊvərˈpaʊərɪŋli/
KK: /oʊvərˈpaʊərɪŋli/
In a way that is too strong or intense to be resisted or ignored.
The aroma of the flowers was overpoweringly sweet, filling the entire room.
Overpoweringly → It is formed from "over-" (meaning excessively or beyond) and "power" (from Old French *poer*, meaning ability or strength) and the suffix "-ingly" (indicating a manner of doing something). The word describes something done in a manner that is excessively strong or overwhelming.
Think of something that is 'beyond' ('over-') what you can handle in terms of 'strength' ('power') — that's why overpoweringly means something is done in an excessively strong way.
No commonly confused words.