Nitrous oxide, especially when used as an anaesthetic.

A common European gull (Xema ridibundus). / An American gull (Leucophaeus atricilla); in summer the head is nearly black, the back slate color, and the five outer primaries black.

An owl (Sceloglaux albifacies) of New Zealand, now probably extinct, named for its cry.

(informal) The spotted hyena (Crocuta crocuta); so called because of the resemblance of its call to human laughter.

(Australia, obsolete) The laughing kookaburra, Dacelo novaeguineae.

The European white-fronted goose (Anser albifrons).

Parodying an ostentatious expression of evilness in online written forums such as chat rooms.

A signature laugh associated with villains in films and acting, sometimes represented by muahahaha or bwahaha.

(idiomatic) An object of ridicule, someone who is publicly ridiculed; the butt of a joke.

(transitive) To respond to a negative situation lightheartedly, as though it were a joke.