It is a Nigerian slang pronounced (Bans) which is an acronym for the famous Nigerian Saying, Boys are not smiling. This slang is used when you are being serious about something, and could also be used for humor.
For Example: "how were your results?" "Ahh BANS" ... For Example: "How did you react to the football score?" "I was BANSING"
Abbreviation for " bitch ass nigga" adjective
If your in the hood, and someone doesn't want to do something you would say " dam you a ban "
Another situation
" why you got to be such a ban you ban."
Banned, Not allowed to do something
You are banned from this site.
To officially get rid of.
Person 1: I might ban you from Fortnite.
Person 2: Thank God