owe vs mortgage

owe is not a noun while mortgage is a noun.

Word	Noun	Adjective	Verb	Adverb
owe	No	No	Yes	No
mortgage	Yes	No	Yes	No

As verbs, mortgage is a hyponym of owe; that is, mortgage is a word with a more specific, narrower meaning than owe:

owe (noun)	mortgage (noun)
	a conditional conveyance of property as security for the repayment of a loan

owe (verb)	mortgage (verb)
be in debt	put up as security or collateral
be obliged to pay or repay
be indebted to, in an abstract or intellectual sense