Merriam-Webster's Collegiate® Dictionary, 11th Edition
INCIDENT
I. noun see: chance
Date: 15th century
something dependent on or subordinate to something else of greater or principal importance,
2. an occurrence of an action or situation that is a separate unit of experience ; happening , an accompanying minor occurrence or condition ; concomitant , an action likely to lead to grave consequences especially in diplomatic matters , see: occurrence
II. adjective
Date: 15th century
occurring or likely to occur especially as a minor consequence or accompaniment , dependent on or relating to another thing in law, falling or striking on something