flint 
/ˈflɪnt/ noun
plural flints /ˈflɪnt/ noun 1 a [noncount] : a hard type of rock that produces a small piece of burning material (called a spark) when it is hit by steel
b [count] : a piece of flint 2 [count] : a piece of metal used for producing a spark
▪ the flint in a cigarette lighter
b [count] : a piece of flint
▪ the flint in a cigarette lighter
