CTFD: An intialism for "Calm The Fuck Down" mosty used in chat forums and email, but having some leakage to vernacular usage. (see-tee-eff-dee)(emphatic)
"During the CoVid-19 lockdown panic with all of those empty shelves in the supermarkets, I wanted managers to put up signs link, 'Attention customers: please CTFD, you don't need to buy 25 rolls of toilet paper'."
Used when telling someone to calm the fuck down now. If the situation is not en emergency the N may be dropped. In a situation that is out of control you can also add OE (or else), OD (or die), or OMO (or move on) to the end to make it quite apparent that you will calm down or get out my face.
Calvin: Get off the damn counter before i skin you.