travel expense vs plural

travel expense and plural both are nouns.

Word	Noun	Adjective	Verb	Adverb
travel expense	Yes	No	No	No
plural	Yes	Yes	No	No

travel expense (noun)	plural (noun)
(frequently plural) expenses incurred by an employee in the performance of the job and usually reimbursed by the employer	the form of a word that is used to denote more than one

travel expense (adjective)	plural (adjective)
	grammatical number category referring to two or more items or units
	composed of more than one member, set, or kind