English Dictionary

Happening by chance, or unexpectedly; taking place not according to the usual course of things; casual; fortuitous; as, an accidental visit.
Source : opted (1073)  - auto

Nonessential; not necessary belonging; incidental; as, are accidental to a play.
Source : opted (1074)  - auto

A property which is not essential; a nonessential; anything happening accidentally.
Source : opted (1075)  - auto

Those fortuitous effects produced by luminous rays falling on certain objects so that some parts stand forth in abnormal brightness and other parts are cast into a deep shadow.
Source : opted (1076)  - auto

A sharp, flat, or natural, occurring not at the commencement of a piece of music as the signature, but before a particular note.
Source : opted (1077)  - auto