- Adjective. Happening by chance, or unexpectedly; taking place not according to the usual course of things; casual; fortuitous.
- Adjective. Nonessential; not necessary belonging; incidental.
- Adjective. (music) Foreign to the key signature or a proper harmony.
- Adjective. unintentional; by accident.
- Noun. A property which is not essential; a nonessential; anything happening accidentally.
- Noun. (context, in plural) 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.
- Noun. (music) A sharp, flat, or natural, occurring not at the commencement of a piece of music as the signature, but before a particular note.