accidental

/ˌak-sə-ˈden-tᵊl/

Middle English, borrowed from Anglo-French accidentel, borrowed from Late Latin accidentālis, from Latin accident-, accidens accident-ālis

adjective

  1. occurring unexpectedly or by chance

  2. happening without intent or through carelessness and often with unfortunate results

  3. arising from extrinsic causes : incidental, nonessential

an accidental discovery

The death was ruled accidental.

accidental fortuitous casual contingent mean not amenable to planning or prediction. accidental stresses chance. fortuitous so strongly suggests chance that it often connotes entire absence of cause.

noun

  1. a nonessential property

  2. a note foreign to a key indicated by a signature

  3. a prefixed sign indicating an accidental