The Collaborative International Dictionary of English v.0.48:
Laryngismus \Lar`yn*gis"mus\, n. [NL., fr. Gr. laryggismo`s a croaking. See Larynx.] (Med.) A spasmodic state of the glottis, giving rise to contraction or closure of the opening. [1913 Webster]WordNet (r) 3.0 (2006):
laryngismus n 1: laryngeal spasm caused by the sudden contraction of laryngeal muscles