n. In general, anything that happens or begins to be without design, or as an unforeseen effect; that which falls out by chance; a fortuitous event or circumstance.n. Specifically, an undesirable or unfortunate happening; an undesigned harm or injury; a casualty or mishap.n. The operation of chance; an undesigned contingency; a happening without intentional causation; chance; fortune: as, it was the result of accident; I was there by accident.n. That which exists or occurs abnormally; something unusual or phenomenal; an uncommon occurrence or appearance.n. Irregularity; unevenness; abruptness.n. An irregularity of surface; an undulation: as, the enemy was favored by the accidents of the ground.n. A non-essential.n. In grammar, a variation or inflection of a word, not essential to its primary signification, but marking a modification of its relation, as gender, number, and case. See accidence.n. Synonyms Chance, mischance, hap, mishap, fortune, misfortune, luck, bad luck, casualty, calamity, disaster.n. Property, Attribute, etc. See quality.