1spark 
/ˈspɑɚk/ noun
plural sparks /ˈspɑɚk/ noun 1 [count] a : a small piece of burning material that comes from a fire or is produced by rubbing or hitting two hard objects together
▪ A spark from the fireplace set the rug on fire. ▪ The car's tailpipe made sparks as it scraped the road.
b : a short, bright flash of electricity between two points
▪ A spark ignites the stove's burner. 2 [noncount] : a quality that makes someone or something enjoyable, interesting, successful, etc.
▪ In its fourth year, the TV series has lost its spark. ▪ She's a talented gymnast but she doesn't have the spark of some of her competitors. 3 [count] : a small amount of something
▪ A spark of hope remains. ▪ Sometimes there were surprising sparks of humor in his letters. ▪ occasional sparks of insight 4 [count] : an action, occurrence, etc., that causes something larger to happen
▪ His death was the spark that ignited the revolution. ▪ Her suggestion was the spark for the entire renovation project.
▪ A spark from the fireplace set the rug on fire. ▪ The car's tailpipe made sparks as it scraped the road.
b : a short, bright flash of electricity between two points
▪ A spark ignites the stove's burner.
▪ In its fourth year, the TV series has lost its spark. ▪ She's a talented gymnast but she doesn't have the spark of some of her competitors.
▪ A spark of hope remains. ▪ Sometimes there were surprising sparks of humor in his letters. ▪ occasional sparks of insight
▪ His death was the spark that ignited the revolution. ▪ Her suggestion was the spark for the entire renovation project.
bright spark
Brit, informal + disapproving : a person who says or does something that seems intelligent but is really not
▪ Who's the bright spark who came up with this rotten idea?
▪ Who's the bright spark who came up with this rotten idea?
sparks fly
◊When sparks fly, it means that two people are either having an argument with each other or are sexually attracted to each other.
▪ The sparks flew [=they had an angry argument] when he arrived late for her special dinner. ▪ Sparks flew when they met for the first time.
▪ The sparks flew [=they had an angry argument] when he arrived late for her special dinner. ▪ Sparks flew when they met for the first time.
