英汉词典

1. 意外的；偶然（发生）的
    An accidental event happens by chance or as the result of an accident, and is not deliberately intended.

accidental的翻译

    e.g. The jury returned a verdict of accidental death...
           陪审团作出意外死亡的正式裁决。
    e.g. His hand brushed against hers; it could have been either accidental or deliberate.
           就在有意无意间，他的手轻轻拂过她的手。