expense vs spending

expense and spending both are nouns.

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

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

Other hypernyms of expense include expenditure, outgo, outlay.

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

expense (verb)	spending (verb)
reduce the estimated value of something