Arnica \Ar"ni*ca\, n. [Prob. a corruption of ptarmica.]

(Bot.) A genus of plants; also, the most important species (Arnica montana), native of the mountains of Europe, used in medicine as a narcotic and stimulant.

Note: The tincture of arnica is applied externally as a remedy for bruises, sprains, etc.

Source: Webster's Revised Unabridged Dictionary (1913)