an inconspicuous way of saying Calm The Fuck Down, derived from the acronym CTFD. It is shorter than saying CTFD and easier to get away with than actually saying Calm the Fuck Down.
Employee: Sorry I'm late…had to stop at the store
Boss: Again?! One more time and you're fired!!
Employee: cat food.
Boss: what was that?
Employee:uhh..nothing, I had to get cat food at the store