C2 [ C ] a very small piece of fire that flies out from something that is burning, or one that is made by rubbing two hard things together, or a flash of light made by electricity火花，火星；电火花
C2 [ S ] a first small event or problem that causes a much worse situation to develop导火线，诱因
[ S ] a feeling or quality that causes excitement愤怒／灵感／生命的火花（等等）
His speech was the spark for major riots.
Her letter was the spark that drove him to commit murder.
C2 to cause the start of something, especially an argument or fighting引起，导致，触发（尤指争论或打斗）