n. The character of being rash; inconsiderate or presumptuous haste; headstrong precipitation in decision or action; temerity; unwarranted boldness.n. A rash act; a reckless or foolhardy deed.n. Synonyms Rashness, Temerity. Rashness has the vigor of the Anglo-Saxon, temerity the selectness and dignity of the Latin. Temerity implies personal danger, physical or other: as, the temerity of undertaking to contradict Samuel Johnson; temerity in going upon thin ice. Rashness is broader in this respect. Roshness goes by the feelings without the judgment; temerity rather disregards the judgment. Temerity refers rather to the disposition, rashness to the conduct. See adventurous.