someone who isn't experienced with girls
"You mean when she told me she wanted to suck my dick she was trying to let me know that I liked her??"

"Dude, you're so girl dumb."
by Gay Mergirl August 31, 2015
A term for queer aligned women/non-binary people to describe the poor choices/dumb ideas that normally rational women/people make when they're thinking about a girl they like.
-"I was supposed to work late tonight and finish up a big project, but that girl from Hinge and I texted all night instead".
-When you're talking to a friend and they literally cannot carry a conversation because they keep thinking about their crush.
-Uhauling

All examples of Dumb Girl Brain
by WhiteStripeTrans July 19, 2021
The amazing number of 18-24 year old dumb girls with smart phones that will instantly take their clothes off and take pictures of themselves in their bathroom and bedroom mirrors while their clueless father is downstairs watching home videos of when she was 3 and learning how to jump rope.
Guy A) Dude...why are are there suddenly so many pictures of hot girl next door types all over internet. Either showing off their tits, or licking each others tits?

Guy B) Dumb Girls with Smart Phones, dude. It's awesome.
by Comics Nut June 12, 2011