Not given to heavy thoughts or thinking, frivolous, not serious.

A breed of poultry.

(idiomatic) To regard without due seriousness; to joke about.

(obsolete, chiefly Victorian) A worker whose duties involve carrying light (i.e., not heavy) packages, as in a bank. / A type of porter ale lighter in color than the typical dark porter.

plural of light globe

plural of light switch

lighting by neon lamps

A neon lamp. / The light from such a lamp.

a magnesium lamp / the intense light from such a lamp

A warning light, especially as a traffic signal indicating stop. / A sign of a brothel. / (idiomatic) Denial to proceed; a ruling out of any possibility.