pen vs writing

pen and writing both are nouns.

Word	Noun	Adjective	Verb	Adverb
pen	Yes	No	Yes	No
writing	Yes	No	No	No

pen (noun)	writing (noun)
female swan	the activity of putting something in written form
a writing implement with a point from which ink flows	the act of creating written works
an enclosure for confining livestock	the work of a writer; anything expressed in letters of the alphabet (especially when considered from the point of view of style and effect)
a correctional institution for those convicted of major crimes	letters or symbols that are written or imprinted on a surface to represent the sounds or words of a language
a portable enclosure in which babies may be left to play	(usually plural) the collected work of an author

pen (verb)	writing (verb)
produce a literary work