pocketknife(n = noun.artifact) pocket knife - a knife with a blade that folds into the handle; suitable for carrying in the pocket;
is a kind of knife
has particulars: clasp knife, jackknife, penknife, flick-knife, flick knife, switchblade, switchblade knife

   A knife with one or more blades, which fold into the handle so as to admit of being carried in the pocket. [1913 Webster]