An acronym/abbreviation meaning "Keep it STUPID
Simple" where "stupid" is functioning as an adverbial intensifier (aka, very). It means to simplify
something a lot and can be compared to the similar "KISS" where KISS means "Keep it simple, stupid" and is a rude and derogatory/condescending way of telling someone to keep
something simple, the sense of "duh, you dumbo!"
I am horrible at math, I am going to
need you to KISS
please!
I am bad at languages and this is confusing me,
please KISS!