Laughing

a. & n.
Laughing falcon (Zoöl.),
a South American hawk (Herpetotheres cachinnans); -- so called from its notes, which resemble a shrill laugh.
Laughing gas (Chem.),
hyponitrous oxide, or protoxide of nitrogen; -- so called from the exhilaration and laughing which it sometimes produces when inhaled. It is much used as an anæsthetic agent.
Laughing goose (Zoöl.),
the European white-fronted goose.
Laughing gull

1. A common European gull (Xema ridibundus); -- called also pewit, black cap, red-legged gull, and sea crow.
2. An American gull (Larus atricilla). In summer the head is nearly black, the back slate color, and the five outer primaries black.
Laughing hyena (Zoöl.),
the spotted hyena. See Hyena.
Laughing jackass (Zoöl.),
the great brown kingfisher (Dacelo gigas), of Australia; -- called also giant kingfisher, and gogobera.
Laughing owl (Zoöl.),
a peculiar owl (Sceloglaux albifacies) of New Zealand, said to be on the verge of extinction. The name alludes to its notes.