outlay vs payment

outlay and payment both are nouns.

Word	Noun	Adjective	Verb	Adverb
outlay	Yes	No	No	No
payment	Yes	No	No	No

As nouns, payment is a hypernym of outlay; that is, payment is a word with a broader meaning than outlay:

Other hypernyms of outlay include defrayal, defrayment.

outlay (noun)	payment (noun)
the act of spending or disbursing money	the act of paying money
money paid out; an amount spent	an act of requiting; returning in kind
	a sum of money paid or a claim discharged