Your pal in a pinch.
Pocket Knife: A knife with one or more folding blades, and small enough to carry in a pocket.
Pocket Knife: A tool that hikers can use to cut their way out of a giant's pocket, if a giant comes along and puts that hiker into its pocket, which is kind of rare. But you never know.
Pocket Knife: A kind of knife suited to whittling a new pocket if one of yours wears out while you are on the trail. These are also good for various general purpose things like cutting cord and putting points on marshmallow sticks, though for nose hairs you really need a good nose hair trimmer. (To avoid unfortunate accidents.)