accidental

sifat adjective

1. Not essential; incidental, secondary.
2. Nonessential to something's inherent nature (especially in Aristotelian thought).
3. Adjusted by one or two semitones, in temporary departure from the key signature.
4. Occurring sometimes, by chance; occasional.

ot noun

1. A property which is not essential; a nonessential; anything happening accidentally.
2. 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.
3. A sharp, flat, or natural, occurring not at the commencement of a piece of music as the signature, but before a particular note.
4. Part of a text that has a mainly structural purpose, such as spelling, punctuation or capitalization.