flint

/flɪnt/

/flɪnt/

Other forms: flints

Flint is a very hard type of rock. Ever since humans first learned to make tools, back in the Stone Age, they've used flint.

Through history, flint has been used for sharp tools, in walls and buildings, for making sparks to start fires, and in jewelry and pottery. You can also use the word figuratively, to mean a quality of hardness or even cruelty in a someone's personality: "The flint in his nature made him unsympathetic even to the most pitiful crying child."

Definitions of flint

1. noun

   a hard kind of stone; a form of silica more opaque than chalcedony
   types:

   gunflint

   the piece of flint that provides the igniting spark in a flintlock weapon

   firestone

   a piece of flint that is struck to light a fire

   flintstone

   pebbles of flint used in masonry construction

   type of:

   silica, silicon dioxide, silicon oxide

   a white or colorless vitreous insoluble solid (SiO2); various forms occur widely in the earth's crust as quartz or cristobalite or tridymite or lechatelierite
2. adjective

   showing unfeeling resistance to tender feelings
   synonyms: flinty, granitic, obdurate, stony

   hardhearted, heartless

   lacking in feeling or pity or warmth