Entry 2 senses Webster, 1913 Glonoin · Glon·o·in · IPA 01 n. Same as Nitroglycerin; -- called also oil of glonoin. 1. Same as Nitroglycerin; -- called also oil of glonoin.[Obs.] Also: oil of glonoin See: Nitroglycerin 2. A dilute solution of nitroglycerin used as a neurotic.(Med.)