(ăk′sĭ-dĕnt)
[Pronunciation]
[L. accidens, happening]

1. An unforeseen occurrence of an unfortunate nature; a mishap.
2. An unexpected complicating event in the course of a disease or following surgery.

accidental, (-dĕn′tăl)
[Pronunciation]
adj.

Subentries:
cerebrovascular accident
radiation accident