outstanding vs owing

outstanding and owing both are adjectives.

Word	Noun	Adjective	Verb	Adverb
outstanding	No	Yes	No	No
owing	No	Yes	No	No

As adjectives, outstanding and owing are synonyms defined as:

Other synonyms of outstanding include undischarged.

outstanding (adjective)	owing (adjective)
having a quality that thrusts itself into attention	owed as a debt
of major significance or importance
distinguished from others in excellence
owed as a debt