The act of using your brain to make a decision.

Abbreviation for:

I DON’T GIVE A FUCK WHAT THE CDC SAYS YOU BE WEARING YOUR MASK

An easy decision made using the brain. As opposed to a 'no brainer', an incorrect term seeing as how all decisions are made using the brain, as pointed out by SourceFed's brilliant Joe Bereta.

When you think about a decision and make the right choice. Like a no-brainer but better.

a girl who sucks dick (gives brains)

A Brainer is when you do something because it had to be done and you knew it was the right thing to do.

when you're excited to learn something new, eg. math, science. it's basically a boner in your brain a.ka brainer.