Definition of "Spark" :
noun: merriment expressed by a brightness or gleam or animation of countenance
"He had a sparkle in his eye."
noun: a momentary flash of light
noun: a small fragment of a burning substance thrown out by burning material or by friction
noun: Scottish writer of satirical novels (born in 1918)
noun: electrical conduction through a gas in an applied electric field
noun: a small but noticeable trace of some quality that might become stronger
"A spark of interest."
verb: put in motion or move to act
verb: emit or produce sparks
"A high tension wire, brought down by a storm, can continue to spark."