minor expense vs incidental expense

minor expense and incidental expense both are nouns.

Word	Noun	Adjective	Verb	Adverb
minor expense	Yes	No	No	No
incidental expense	Yes	No	No	No

As nouns, minor expense and incidental expense are synonyms defined as:

minor expense and incidental expense: (frequently plural) an expense not budgeted or not specified

Other synonyms of minor expense include incidental.

minor expense (noun)	incidental expense (noun)
(frequently plural) an expense not budgeted or not specified	(frequently plural) an expense not budgeted or not specified