A spark is a small fire particle produced when wood burns or when two pieces of metal or stone hit each other. Figuratively, a spark is an intense trace of vitality and excitement, especially an attraction between two people. As a verb, spark means 'to release sparks or to start a fire,' and figuratively it means 'to start something.'
If you sit too close to the fire, the sparks will get you.
José and Lucy never went on a second date because there was no spark.
The CEO's attitude caused a spark of anger in all his employees, but nobody could say anything.
The metal started sparking as soon as the mechanic turned on the machine.
The new taxes sparked a riot.
sparks fly: an informal way of saying that things get lively or heated when people meet. For example, "Sparks fly whenever you talk to each other; you're obviously in love!" or "Everyone in the room was angry and the atmosphere was very tense; you could tell sparks were going to fly at any moment."
A spark is also an old-fashioned word for an elegant young man who is too concerned about the way he looks. People don't use this anymore but you might see it in older novels. We can also call this kind of man a fop.
Sparkle is a related word that means 'to emit or reflect bright points of light.' Because the points of light change position, they can seem a bit like sparks being emitted by a fire.
sparkless (adjective), sparklessly (adverb)
Spark dates back to before 900 and the noun comes from the Old English word spearca. It is similar to the Middle Dutch and Middle Low German word sparka. The verb is not as old. It comes from the Middle English word sparken, which also appears in Middle Dutch and Low German.