Damb is a word created by twitch streamer, Wallibear. Damb is just another word for damn. It is often said between Wallibear and fellow twitch streamer Purpled.
Short for: Don't Acronym Me, Bitch! When some (likely millennial) doucheface comes at you with all these acronyms like you have nothing better to do than learn all the "cool" abbreviations they have spent their worthless time coming up with or learning and drops them like they are common knowledge, use this to kill all that noise.
"OMG, IMO AFAIK TBH FAWC J4F TIL math is E123!"
"DAMB!"