A term used in Japan literally meaning'flat-chest', 'titless' or something along the lines of lacking breasts. Can be mistranslated as 'pancake'. Used primarily in anime as a derogatory term
Guy: "Dude, John is really depressed."
Guy 2: "He seems fine."
guy: "Not at all man. I heard he's been fat chicking it for 3 weeks straight."
Guy 2: "Holy shit."