What is the meaning of Penknife?

A small utility 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.

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.

A pocket-knife, especially a small one.

Alternative form of penne knyfe

Source: wiktionary.org