pen

(noun) a writing implement with a point from which ink flows.

(noun) an enclosure for confining livestock.

(noun) a portable enclosure in which babies may be left to play. Synonyms: playpen.

(noun) a correctional institution for those convicted of major crimes. Synonyms: penitentiary.

(noun) female swan.

(verb) produce a literary work. Synonyms: write, compose, indite. Examples: "She composed a poem." "He wrote four novels."