incidental expense vs minor expense

incidental expense and minor expense both are nouns.

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

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

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

Other synonyms of incidental expense include incidental.

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