expense vs outgo

expense and outgo both are nouns.

Word	Noun	Adjective	Verb	Adverb
expense	Yes	No	Yes	No
outgo	Yes	No	Yes	No

As nouns, outgo is a hypernym of expense; that is, outgo is a word with a broader meaning than expense:

Other hypernyms of expense include expenditure, outlay, spending.

expense (noun)	outgo (noun)
a detriment or sacrifice	money paid out; an amount spent
amounts paid for goods and services that may be currently tax deductible (as opposed to capital expenditures)
money spent to perform work and usually reimbursed by an employer

expense (verb)	outgo (verb)
reduce the estimated value of something	be or do something to a greater degree