IPA: /ˈbreɪniər/
KK: /ˈbrenɪər/
More intelligent or clever than someone or something else.
She is brainier than her classmates, often solving problems faster.
Brainier → It is formed from "brain" (from Old English "brægen", meaning the organ of thought) and "-ier" (a comparative suffix indicating more). The word "brainier" means having more brain or intelligence than another.
Think of someone who has 'more brain' — the suffix '-ier' indicates a comparison, so 'brainier' means more intelligent.