penknife noun 3verb 1forms 4 noun3 •A small pocketknife; (loosely) any pocketknife.Limpet's penknife was on the table, and he snatched that up and commenced stabbing it into the cork, whether as a means of getting it out, or merely as a relief to his passion, it is difficult to say. — 1913 •A small knife designed for safe and convenient storage, typically in the form of a miniature clasp-knife, or with blade retractable into the handle. •(no longer used) A small knife for cutting the points of quill feathers or reeds into nibs to provide or repair writing implements, early versions were commonly small sheath knives. verb1 •To cut or carve with a penknife. formspenknifed · penknifing · penknifes · penknives