expenditure vs outlay

expenditure and outlay both are nouns.

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

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

Other hypernyms of expenditure include disbursal, disbursement, spending.

As nouns, expenditure and outlay are synonyms defined as:

Other synonyms of expenditure include outgo, spending.

expenditure (noun)	outlay (noun)
the act of spending money for goods or services	the act of spending or disbursing money
the act of consuming something	money paid out; an amount spent
money paid out; an amount spent