1. a. A small, dry, one-seeded fruit of a cereal grass, having the fruit and the seed walls united. Also called caryopsis. b. The fruits of cereal grasses especially after having been harvested, considered as a group.

2. Cereal grasses considered as a group: a field of grain.

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. A unit of weight in the U.S. Customary System, an avoirdupois unit equal to 0.002285 ounce (0.065 gram).

6. The arrangement, direction, or pattern of the fibrous tissue in wood.

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. b. An essential quality or characteristic.

14. Archaic. Color; tint.

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.