v.i.nội động từđấm bốc, đánh nhauThe boxers were duking it out in the ring for the championship title.
v.t.ngoại động từđấm ai đóHe was duking his opponent with a series of jabs and hooks.
v.t./i.động từ (ngoại/nội)cạnh tranh khốc liệtThey were duking it out over who would get the last slice of pizza.