Webster's Revised Unabridged Dictionary · 1913

Accident

Accident ({not transcribed}) , noun

[French accident, from Latin accidens, -dentis, present participle of accidere to happen; ad + cadere to fall. See Cadence, Case.]

1.
Literally, a befalling; an event that takes place without one's foresight or expectation; an undesigned, sudden, and unexpected event; chance; contingency; often, an undesigned and unforeseen occurrence of an afflictive or unfortunate character; a casualty; a mishap; as, to die by an accident.
Of moving accidents by flood and field. — Shakespeare
Thou cam'st not to thy place by accident: It is the very place God meant for thee. — Trench
2.
(Grammar) A property attached to a word, but not essential to it, as gender, number, case.
3.
(Heraldry) A point or mark which may be retained or omitted in a coat of arms.
4.
(a) (Log.) A property or quality of a thing which is not essential to it, as whiteness in paper; an attribute.
(b)
(Log.) A quality or attribute in distinction from the substance, as sweetness, softness.
5.
Any accidental property, fact, or relation; an accidental or nonessential; as, beauty is an accident.
This accident, as I call it, of Athens being situated some miles from the sea. — J. P. Mahaffy
6.
Unusual appearance or effect. [Obsolete] — Chaucer

Accident, in Law, is equivalent to casus, or such unforeseen, extraordinary, extraneous interference as is out of the range of ordinary calculation.