Semi-Chub
A boner in an early stage of development. It is no longer flacid, but not quite erect yet.
Dude "Hey Ben did you see Lupitas ass during swimming today" Ben "Hell yeah, she gave me a little bit of semi-chub"
semi chub
to have a partial erection of the penis
i saw my grandma naked but i wasn't sure if i liked it or not so i had a semi chub.