DMG: Acronym, Dungeon Master's Guide.

Powergaming [verb]: The practice of optimising games above all other concerns, even fun.

Chud [noun]: A horrible creature that lives in the sewers and survives by licking piss off of boots. Sort like a goblin or ghoul.

Slop [noun]: Art that is of low quality.

Treantmonk [proper noun]: popular Youtuber that designs genuinely impressive powergaming builds for 5e, but frequently uses bad-faith arguments like this.

"X has been a disaster for Y": A snowclone, ah, alas, I forget where this one comes from.