The opposite of the glow up. Used to describe someone who used to be attractive and has, with age, actually decreased in attractiveness.

A jack off buddy (from 'cum' /'come', meaning 'semen', and 'companion'); a friend that you get together with for sessions of solo or mutual masturbation
Variant of: cumpanion (from 'companion' & 'cum'); jack off buddy & wank bud & JO buddy
Similar to: fuck buddy

A glow down is like the opposite of a glow up. Instead of someone getting really hot over a period of time, the person gets more ugly.