1. Not of prime or central importance; SYN. nonessential.
2. (Sometimes followed by 'to') Minor or casual or subordinate in significance or nature or occurring as a chance concomitant or consequence; SYN. incident.
accompanying · attendant · concomitant · incident · incidental to · inessential · nonessential · omissible · parenthetic · parenthetical · peripheral · related · related to · secondary · unessential
An item that is incidental.
incidental expense · minor expense