accidental (
http://definr.com/accidental)
adj 1: associated by chance and not an integral part; "poetry is
something to which words are the accidental, not by
any means the essential form"- Frederick W. Robertson;
"they had to decide whether his misconduct was
adventitious or the result of a flaw in his character"
[syn:
adventitious]
2: occurring or appearing or singled out by chance; "their
accidental meeting led to a renewal of their friendship";
"seek help from casual passers-by"; "a casual meeting"; "a
chance occurrence" [syn:
casual,
chance(a)]
3: without intention; especially resulting from heedless
action; "with an inadvertent gesture she swept the vase
off the table"; "accidental poisoning";"an accidental
shooting" [syn:
inadvertent]
n : a notation that makes a note sharp or flat or natural
although that is not part of the key signature