It can mean various things. It dependens on how you use it in a sentence. You can use it in negative term or positive term. Negative term- awful, terrible, not a good situation to be in. Positive term- awesome, happy at what just happened, someone achiving something that you like.

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