Weed  —n. 1 wild plant growing where it is not wanted. 2 thin weak-looking person or horse. 3 (prec. By the) slang a marijuana. B tobacco. —v. 1 a clear (an area) of weeds. B remove unwanted parts from. 2 (foll. By out) a sort out and remove (inferior or unwanted parts etc.). B rid of inferior parts, unwanted members, etc. 3 cut off or uproot weeds. [old english]