I. in ‧ ci ‧ den ‧ tal 1 /ˌɪnsəˈdentl◂, ˌɪnsɪˈdentl◂/ BrE AmE adjective
1 . happening or existing in connection with something else that is more important:
Increased motivation is more than an incidental benefit of reward schemes.
incidental to
companies that carry out investment business that is incidental to their main activity
2 . [not before noun] naturally happening as a result of something
incidental to
Drinking too much is almost incidental to bartending.
II. incidental 2 BrE AmE noun [countable usually plural]
something that you have to do, buy etc which you had not planned to:
Carry extra cash for taxis, tips, and other incidentals.