From Longman Dictionary of Contemporary Englishpocket knifeˈpocket knife noun (plural pocket knives) [countable] Da small knife with one or more blades that fold into the handle SYN penknife
Examples from the Corpus
pocket knife• Me, I like to carry a pocket knife.• After some thought, I was able to cut the rope near the stern with my pocket knife lashed to a paddle.• Where the water dripped on to my dirt floor, I scraped a trench with my pocket knife to let it drain out.• Cokley managed to remove a small pocket knife from his pocket and cut Deering on the leg. 