What is Brainfreeze?
1.
N. Ipsilateral, temporal, orbital and or bilateral pain resulting from rapid cooling of the spheno-palantine ganglion (roof of mouth), often a result of ice-cream or slurpees, although any cold substance can trigger such a response. The pain is a result of dialated blood vessels in the brain brought on by spasms of the nerve endings and typically peaks in about 20 seconds from the point of ingestion.
After rapidly ingesting the Slurpee, Bob winced in pain as if he were having a migraine.
2.
when its so cold out, and you ejaculate, the skeet freezes on the head of your dick.
Tyrone: Man, it's so cold I'mma bout to have a brainfreeze
Alan: Me and Shawna were having sex in the park last night, and I brainfreezed it was so cold.
See
3.
When you (a male) are having sex with someone's ear and you splooge all into the person's ear.
I brainfreezed my girlfriend last night.