n.1. a. A small, dry, one-seeded fruit of a cereal grass, having the fruit and the seed walls united: a single grain of wheat; gleaned the grains from the ground one at a time. Also called caryopsis.
b. The fruits of cereal grasses especially after having been harvested, considered as a group: The grain was stored in a silo.
2. a. A cereal grass: Wheat is a grain grown in Kansas.
b. Cereal grasses considered as a group: Grain is grown along the river.
3. a. A relatively small discrete particulate or crystalline mass: a grain of sand.
b. A small amount or the smallest amount possible: hasn't a grain of sense.
4. Aerospace A mass of solid propellant.
5. Abbr. gr. A unit of weight in the US Customary System, an avoirdupois unit equal to 0.002285 ounce (0.065 gram).
6. a. The markings, pattern, or texture of the fibrous tissue in wood: Cherry wood has a fine grain.
b. The direction of such markings: cut a board with the grain.
7. a. The side of a hide or piece of leather from which the hair or fur has been removed.
b. The pattern or markings on this side of leather.
8. The pattern produced, as in stone, by the arrangement of particulate constituents.
9. The relative size of the particles composing a substance or pattern: a coarse grain.
10. A painted, stamped, or printed design that imitates the pattern found in wood, leather, or stone.
11. The direction or texture of fibers in a woven fabric.
12. A state of fine crystallization.
13. a. Basic temperament or nature; disposition: It goes against my grain to ask for help.
b. An essential quality or characteristic: "Toughness as a virtue ... is, needless to say, fully embedded in the American grain" (Benjamin DeMott).
14. Archaic Color; tint.
v.tr.1. To cause to form into grains; granulate.
2. To paint, stamp, or print with a design imitating the grain of wood, leather, or stone.
3. To give a granular or rough texture to.
4. To remove the hair or fur from (hides) in preparation for tanning.