Merging the already hasty and dismissive way of saying bye - "Kthxbai" with the other dismissive phrase "Bye Felicia" (used when one dislikes the person in question who is thus referred to as "Felicia", and everyone is glad to see this person leave, referencing a scene out of the movie "Friday"). The combined phrase of "Kthxbai Felicia" then becomes extra and extremely dismissive - useful when neither original phrase is enough on their own to convey how much dislike you have regarding the person in question and how much you want them gone asap.
Disliked Person - insert any number of inflammatory comment(s), or an extremely dumb question, or other annoying commentary directed towards you
You - Offer them your full sass and any burns countering and in response to the prior commentary, followed by "Kthxbai Felicia"
Disliked Person is then expected to storm off, quickly removing themselves from the room (and everyone present may then applaud their swift exit).

Toxic co-worker is talking trash about you to other co-workers in the breakroom. You happen to walk in and overhear it and you fire off a sassy burn response, followed by "Kthxbai Felicia"... the toxic co-worker which no one actually likes then storms off and everyone applauds their exit.
by lolwutzup August 10, 2019