The Collaborative International Dictionary of English v.0.48:
cyclopropane \cyclopropane\ n. a colorless flammable gas (C3H6) with a three-carbon ring, sometimes used as an anesthetic. [WordNet 1.5]WordNet (r) 3.0 (2006):
cyclopropane n 1: a colorless flammable gas sometimes used as an inhalation anesthetic