Enough to fill a pen.

present participle of pen in

(Cockney rhyming slang) A stink.

A pen, similar in size and shape to a pencil, having an internal chamber filled with a viscous, quick-drying ink that is dispensed at the tip during use by the rolling action of a metal sphere (around 0.7 mm to 1 mm in diameter).

A fictitious name used by an author in place of their actual name; a writer's pseudonym.

Alternative form of pen name

A pen containing a reservoir of ink, which is fed to a writing nib automatically.

(idiomatic) A manner, means, or tone of expression had by a written work, characterized by spitefulness, defamation, and/or intimidation directed toward a person, organization, or point of view.

a pen used in graphic design and calligraphy for drawing precise lines of various thicknesses

Alternative spelling of penfriend