outline vs limn

outline is a noun but limn is not a noun.

Word	Noun	Adjective	Verb	Adverb
outline	Yes	No	Yes	No
limn	No	No	Yes	No

As verbs, outline and limn are synonyms defined as:

Other synonyms of outline include delineate.

outline (noun)	limn (noun)
a schematic or preliminary plan
a sketchy summary of the main points of an argument or theory
the line that appears to bound an object

outline (verb)	limn (verb)
describe roughly or briefly or give the main points or summary of	make a portrait of
trace the shape of	trace the shape of
draw up an outline or sketch for something