deadleg noun 4verb 1forms 3 noun4 •An isolated section of pipeline that does not usually carry a flow.There should be minimum deadleg between the valve and main process unit and, if possible, means for cleaning the deadleg. — 1996 •A vehicle that is traveling on a leg of its route in which it does not carry any cargo.Companies can transport on a nationwide basis but usually only carry their products out and have a deadleg on the return trip, e.g., the sugar distributors. — 1984 •A lazy or weak person.I was a bit of a deadleg in them days. You know, footloose and inclined to be rather flirtatious with the ladies. — 1961 •A movement in which the hips and knees are kept straight and stiff and the ankle is flexed. verb1 •To knee someone in the thigh. formsdeadlegged · deadlegging · deadlegs