Correct spelling for the English word "stagnin" is [stˈaɡnɪn], [stˈaɡnɪn], [s_t_ˈa_ɡ_n_ɪ_n] (IPA phonetic alphabet).
Trade name of a styptic preparation derived from the spleen of the horse.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.