IPA: /ˈbreɪnˌpaʊər/
KK: /ˈbrenˌpaʊər/
The mental ability to think, learn, and understand things.
She used her brainpower to solve the complex math problem.
Brainpower → It is formed from "brain" (from Old English "brægen", meaning the organ of thought) and "power" (from Latin "potere", meaning to be able or have strength). The term "brainpower" refers to the mental capacity or ability to think and reason.
Think of the 'brain' as the organ of thought and 'power' as strength — together, they describe the strength of your thinking ability.
No commonly confused words.