Bak is an internet accronmym for back at keyboard.

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

Acronym for a Bad Ass Kid. It is not meant in a positive way, it means the child is naughty, disrespectful, backtalking, disobedient, spoiled, etc. etc.

Slang for 'back'. Lazy people use this a lot to signal their friends after they state BRB or BBL.

BAK stands for Billboard All Kill invented by the South Korean Boy Band BTS who achieved #10 on BB HOT 100 with Fake Love , got #1 on BB 200 Albums with LY_Tear , #1 on BB Digital Songs with Fake love and having all 11 tracks of LY_Tear charting on World Digital Song Sales.

the state of going african on an individual.

Comes from bak (back at keyboard). You can name a person just like that when he shows signs of anti-social behaviour. The worst case scenario is that he will find family tables as an excuse to avoid going out, despite that he will be playing video games all night.