familiar UK /fəˈmɪl.i.ə/US /fəˈmɪl.jəɹ/adjective 4noun 5forms 3 adjective4 •already known, because it has been seen or heard beforeThere’s a familiar face; that tune sounds familiar. •Acquainted.I'm quite familiar with this system; she's not familiar with manual gears. •Intimate or friendly.We are on familiar terms now; our neighbour is not familiarDon’t be familiar with me, boy! •Of or pertaining to a family; familial.familiar feuds — 1822 noun5 •An attendant spirit, often in animal or demon form.The witch’s familiar was a black cat. •A member of a pope's or bishop's household. •(historical) The officer of the Inquisition who arrested suspected people. •(no longer used) A member of one's family or household. •(no longer used) A close friend. formsfamiliars · more familiar · most familiar