When a girl uses a guy to get answers, favors, money, etc.
Person A: she just texted me again she likes me and wants me to help her with maths
Person B: she's obviously bigbraining you
When someone has a brain too big it malfunctioning
Jaani is showing signs of Bigbrainity
1: Someone with a brain so f-en big, it literally makes them more dumb than smart. 2: a dumb ass nerd
I have I bigbrain and you have a small ass brain like a hamster eating a horse butt.