frat /fɹæt/noun 1verb 1forms 3 noun[before a noun]1 •Shortened form of fraternity, college organization.See you at the frat house.All the frats will be there. verb1 •(slang) To fraternize.[…] "fratting" (fraternising) a bit with the frauleins, who were apparently not at all reluctant to be "fratted" with. — 1967 formsfratted · fratting · frats
