Emily Dickinson Lexicon

AC'CI-DENT, n. [L. accidens, falling, from ad and cado, to fall; W. codum, a fall, cwyzaw, to fall; Ir. kudaim; Corn. kotha; Arm. kuetha, to fall. See Case and Cadence. Class Gd.]

1. A coming or falling; an event that takes place without one's foresight or expectation; an event which proceeds from an unknown cause, or is an unusual effect of a known cause, and therefore not expected; chance; casualty; contingency.
2. That which takes place or begins to exist without an efficient intelligent cause and without design. All of them, in his opinion, owe their being to fate, accident, or the blind action of stupid matter. – Dwight.
3. In logic, a property, or quality of a being which is not essential to it, as whiteness in paper. Also all qualities are called accidents, in opposition to substance, as sweetness, softness, and things not essential to a body, as clothes. – Encyc.
4. In grammar, something belonging to a word, but not essential to it, as gender, number, inflection. – Encyc.
5. In heraldry, a point or mark, not essential to a coat of arms. – Encyc.