flint

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A very hard, fine-grained quartz that sparks when struck with steel.
2. n. A piece of flint used to produce a spark.
3. n. A small solid cylinder of a spark-producing alloy, used in lighters to ignite the fuel.
4. n. A piece of flint used as a tool by prehistoric humans.
5. n. Something resembling flint in hardness: a jaw of flint.

Century Dictionary and Cyclopedia

1. n. A form of silica, somewhat allied to chalcedony, but more opaque, and with less luster. It is usually of a light-gray or brownish color. It has a peculiarly well-marked conchoidal fracture, and can easily be broken up into fragments having sharp cutting edges. For this reason, and because of its hardness, which is proverbial, flint was most extensively used in prehistoric times for all kinds of cutting implements. The use of flint as a means of striking fire with a steel, and especially as a part of the once almost universally used musket-lock, is well known. Flint occurs in large quantity in the form of nodules, and even sheets or beds, in the chalk of England and France, and has been formed by the slow replacement of carbonate of lime by silica held in solution in water. It is abundant in the United States, generally in massive forms. The exterior of most flints is of a lighter color than the interior, this difference being caused by a rearrangement of the particles of the silica.
2. n. A piece of flinty stone used for any purpose, as for striking fire in a flint-lock musket or otherwise, or in the form of an implement. See cut under flint-lock.
3. n. Figuratively, something very hard or obdurate: as, he was flint against persuasion.
4. Made or composed of flint.
5. Hard and firm, as if made of flint: as, flint corn or flint wheat.
6. n. Sheepskin dried in the sun.
7. n. An abbreviation of flint-glass.

Wiktionary

1. n. A hard, fine-grained quartz that fractures conchoidally and generates sparks when struck.
2. n. A piece of flint, such as a gunflint, used to produce a spark.
3. n. A small cylinder of some other material of the same function in a cigarette lighter, etc.
4. v. To furnish or decorate an object with flint.

GNU Webster's 1913

1. n. A massive, somewhat impure variety of quartz, in color usually of a gray to brown or nearly black, breaking with a conchoidal fracture and sharp edge. It is very hard, and strikes fire with steel.
2. n. A piece of flint for striking fire; -- formerly much used, esp. in the hammers of gun locks.
3. n. Anything extremely hard, unimpressible, and unyielding, like flint.

WordNet 3.0

1. n. a city in southeast central Michigan near Detroit; automobile manufacturing
2. adj. showing unfeeling resistance to tender feelings
3. n. a hard kind of stone; a form of silica more opaque than chalcedony
4. n. a river in western Georgia that flows generally south to join the Chattahoochee River at the Florida border where they form the Apalachicola River