expenditure vs using up

expenditure and using up both are nouns.

Word	Noun	Adjective	Verb	Adverb
expenditure	Yes	No	No	No
using up	Yes	No	No	No

As nouns, expenditure and using up are synonyms defined as:

Other synonyms of expenditure include consumption.

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