flint

Etymology

From Middle English flynt, flint, from Old English flint, from Proto-West Germanic *flint, from Proto-Germanic *flintaz (compare Dutch vlint, flint (“flint, cobblestone”), German Flins, Flint (“flint, pebble”), Danish flint (“flint”)), from Proto-Indo-European *splind- (“to split, cleave”) (compare Irish slinn (“slate, shingle”), Ancient Greek πλίνθος (plínthos)), from *(s)plei- (“to split”). More at split.

noun

1. 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.
2. A piece of flint, such as a gunflint, used to produce a spark by striking it with a firestriker.
3. A small cylinder of some other material of the same function in a cigarette lighter, etc.
4. A type of maize/corn with a hard outer hull.
5. (figurative) Anything figuratively hard.

verb

1. (transitive) To furnish or decorate an object with flint.