A small pocketknife; a little knife with a blade which folds into the hand. Penknives frequently incorporate other resources such corkscrews, and tend to be smaller than pocketknives as an organization.
a tiny pocketknife; previously, a knife useful for making and mending quill pens.
a little pocket-knife: so called from the previous use within making and mending quill pencils.
a small pocketknife; originally used to cut quill pencils