Downriver Perm Share definition Flag The act of cumming in a girls hair, then when she wakes up in the morning her hair is perm like. Yo, I gave that bitch I met at the wheat a downriver perm last night. Downriver Perm by Devil boner April 24, 2013 0 0 Get merch Get the Downriver Perm mug. Buy Now — $32.95 See more merch