Gumpdere 

Derived from the Japanese word 'ぐんぴる' meaning 'to be a gump'

Gumpdere is used to describe anime girls who have an iq below 40.

Guy 1: My waifu is ____!
Guy 2: Wtf man, she's a total Gumpdere!

Gumpdere by Jaybubski September 3, 2018