"apparatus for drawing air or gas through a tube," 1845, agent noun from Latin aspirare (see aspire (v.)).
proprietary name for a type of liquid gas sold in Britain, 1936, from Latin calor, literally "heat" (from PIE root *kele- (1) "warm").
mid-14c., verbal noun from laugh (v.). Laughing matter (usually with negative) is from 1560s. Nitrous oxide has been called laughing gas since 1842 (for its exhilarating effects). Humphry Davy, experimenting with the gas, discovered these as far back as 1779: "When I took the bag from my mouth, I immediately laughed. The laughter was involuntary, but highly pleasurable, accompanied by a thrill all through me."