LET ONE HAVE IT

{v. phr.} 1a. {slang} To hit hard. * /He drew back his fist and let the man have it./ * /Give him a kick in the pants; let him have it!/ Syn.: GIVE IT TO. 1b. {slang} To use a weapon on; to shoot or knife. * /The guard pulled his gun and let the robber have it in the leg./ Compare: OPEN UP. 1c. or