noun A hard, fine-grained quartz that fractures conchoidally and generates sparks when struck against a material such as steel, because tiny chips of the steel are heated to incandescence and burn in air.
He used flint to make a fire.
noun A piece of flint, such as a gunflint, used to produce a spark by striking it with a firestriker.
He used a flint to make a fire.
noun A small cylinder of some other material of the same function in a cigarette lighter, etc.
noun A variety of maize/corn with a hard outer hull.