Definitions of accidental:
- noun: a musical notation that makes a note sharp or flat or natural although that is not part of the key signature
- adjective: without intention (especially resulting from heedless action)
Example: "Accidental poisoning"
- adjective: associated by chance and not an integral part
Example: "Poetry is something to which words are the accidental, not by any means the essential form- Frederick W. Robertson"
- adjective: occurring or appearing or singled out by chance
Example: "Their accidental meeting led to a renewal of their friendship"