A phrase used when someone tries to be funny but he/she cannot.

It's specially used with a hashtag as a reply to an unfunny joke.
A: Hey, this phrase is not in longman dictionary.
B: Yes, but it is in Snell's anatomy. (It isn't actually)
A: #henbrain
by KnightKingV2 March 22, 2018
Get a Henbrain mug for your brother Callisto.