outline vs boundary

outline and boundary both are nouns.

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

As nouns, boundary is a hypernym of outline; that is, boundary is a word with a broader meaning than outline:

Other hypernyms of outline include bound, bounds.

outline (noun)	boundary (noun)
a schematic or preliminary plan	the greatest possible degree of something
a sketchy summary of the main points of an argument or theory	the line or plane indicating the limit or extent of something
the line that appears to bound an object	a line determining the limits of an area

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