spark

Concise Oxford English Dictionary © 2008 Oxford University Press:
spark1

▶noun

• 1 a small fiery particle thrown off from a fire, alight in ashes, or produced by striking together two surfaces.

• 2 a light produced by a sudden disruptive electrical discharge through the air.

  ■ a discharge such as this serving to ignite the explosive mixture in an internal-combustion engine.

• 3 a small but concentrated amount or trace: a tiny spark of anger.

  ■ a sense of liveliness and excitement.

▶verb

• 1 emit sparks.

  ■ produce sparks at the point where an electric circuit is interrupted.

• 2 ignite.

• 3 (usu. spark something off) provide the stimulus for.

– phrases
spark out Brit. informal completely unconscious.

– derivatives
sparkless adjective.

– origin OE spærca, spearca, of unknown origin.

Concise Oxford English Dictionary © 2008 Oxford University Press:
spark2

▶noun (in phr. bright spark) a lively person. ▶verb archaic engage in courtship.

– derivatives
sparkish adjective.

– origin C16: prob. from spark1.