The Collaborative International Dictionary of English v.0.48:

Flint \Flint\, n. [AS. flint, akin to Sw. flinta, Dan. flint;
   cf. OHG. flins flint, G. flinte gun (cf. E. flintlock), perh.
   akin to Gr. ? brick. Cf. Plinth.]
   1. (Min.) 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.
      [1913 Webster]

   2. A piece of flint for striking fire; -- formerly much used,
      esp. in the hammers of gun locks.
      [1913 Webster]

   3. Anything extremely hard, unimpressible, and unyielding,
      like flint. "A heart of flint." --Spenser.
      [1913 Webster]

   Flint age. (Geol.) Same as Stone age, under Stone.

   Flint brick, a fire made principially of powdered silex.

   Flint glass. See in the Vocabulary.

   Flint implements (Arch[ae]ol.), tools, etc., employed by
      men before the use of metals, such as axes, arrows,
      spears, knives, wedges, etc., which were commonly made of
      flint, but also of granite, jade, jasper, and other hard
      stones.

   Flint mill.
      (a) (Pottery) A mill in which flints are ground.
      (b) (Mining) An obsolete appliance for lighting the miner
          at his work, in which flints on a revolving wheel were
          made to produce a shower of sparks, which gave light,
          but did not inflame the fire damp. --Knight.

   Flint stone, a hard, siliceous stone; a flint.

   Flint wall, a kind of wall, common in England, on the face
      of which are exposed the black surfaces of broken flints
      set in the mortar, with quions of masonry.

   Liquor of flints, a solution of silica, or flints, in
      potash.

   To skin a flint, to be capable of, or guilty of, any
      expedient or any meanness for making money. [Colloq.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

flint
    adj 1: showing unfeeling resistance to tender feelings; "his
           flinty gaze"; "the child's misery would move even the
           most obdurate heart" [syn: flinty, flint, granitic,
           obdurate, stony]
    n 1: a hard kind of stone; a form of silica more opaque than
         chalcedony
    2: a river in western Georgia that flows generally south to join
       the Chattahoochee River at the Florida border where they form
       the Apalachicola River [syn: Flint, Flint River]
    3: a city in southeast central Michigan near Detroit; automobile
       manufacturing

Moby Thesaurus II by Grady Ward, 1.0:

29 Moby Thesaurus words for "flint":
   adamant, bone, brand, brick, butane lighter, cement,
   cigarette lighter, concrete, diamond, firebrand, flambeau,
   flint and steel, granite, heart of oak, igniter, iron, light,
   lighter, marble, nails, oak, portfire, rock, sparker, spill, steel,
   stone, taper, torch



Easton's 1897 Bible Dictionary:

Flint
   abounds in all the plains and valleys of the wilderness of the
   forty years' wanderings. In Isa. 50:7 and Ezek. 3:9 the
   expressions, where the word is used, means that the "Messiah
   would be firm and resolute amidst all contempt and scorn which
   he would meet; that he had made up his mind to endure it, and
   would not shrink from any kind or degree of suffering which
   would be necessary to accomplish the great work in which he was
   engaged." (Comp. Ezek. 3:8, 9.) The words "like a flint" are
   used with reference to the hoofs of horses (Isa. 5:28).


U.S. Gazetteer Places (2000):

Flint, MI -- U.S. city in Michigan
   Population (2000):    124943
   Housing Units (2000): 55464
   Land area (2000):     33.632912 sq. miles (87.108838 sq. km)
   Water area (2000):    0.429835 sq. miles (1.113267 sq. km)
   Total area (2000):    34.062747 sq. miles (88.222105 sq. km)
   FIPS code:            29000
   Located within:       Michigan (MI), FIPS 26
   Location:             43.027577 N, 83.693996 W
   ZIP Codes (1990):     48502 48503 48505 48507
   Note: some ZIP codes may be omitted esp. for suburbs.
   Headwords:
    Flint, MI
    Flint