penning vs reference

penning and reference both are nouns.

Word	Noun	Adjective	Verb	Adverb
penning	Yes	No	No	No
reference	Yes	No	Yes	No

penning (noun)	reference (noun)
the act of creating written works	the act of referring or consulting
	the most direct or specific meaning of a word or expression; the class of objects that an expression refers to
	the relation between a word or phrase and the object or idea it refers to
	a formal recommendation by a former employer to a potential future employer describing the person's qualifications and dependability
	a remark that calls attention to something or someone
	a short note recognizing a source of information or of a quoted passage
	a book to which you can refer for authoritative facts
	an indicator that orients you generally
	a publication (or a passage from a publication) that is referred to
	(computer science) the code that identifies where a piece of information is stored

penning (verb)	reference (verb)
	refer to