a small, hard seed, esp. the seed of a food plant such as wheat, corn, rye, oats, rice, or millet.

the gathered seed of food plants, esp. of cereal plants.

such plants collectively.

any small, hard particle, as of sand, gold, pepper, or gunpowder.

the smallest unit of weight in most systems, originally determined by the weight of a plump grain of wheat. In the U.S. and British systems, as in avoirdupois, troy, and apothecaries' weights, the grain is identical. In an avoirdupois ounce there are 437.5 grains; in the troy and apothecaries' ounces there are 480 grains (one grain equals 0.0648 gram).

the smallest possible amount of anything

a grain of truth.

the arrangement or direction of fibers in wood, or the pattern resulting from this.

the direction in which the fibers of a piece of dressed wood, as a board, rise to the surface

You should work with or across the grain, but never against.

the side of leather from which the hair has been removed.

a stamped pattern that imitates the natural grain of leather

used either on leather to simulate a different type of natural leather, or on coated cloth.

Textiles .

the fibers or yarn in a piece of fabric as differentiated from the fabric itself.

the direction of threads in a woven fabric in relation to the selvage.

the lamination or cleavage of stone, coal, etc.

Metallurgy . any of the individual crystalline particles forming a metal.

Jewelry . a unit of weight equal to 50 milligrams or 1 / 4 carat, used for pearls and sometimes for diamonds.

the size of constituent particles of any substance; texture

sugar of fine grain.

a granular texture or appearance

a stone of coarse grain.

a state of crystallization

boiled to the grain.

temper or natural character

two brothers of similar grain.

Rocketry . a unit of solid propellant.

Obsolete . color or hue.

to form into grains; granulate.

to give a granular appearance to.

to paint in imitation of the grain of wood, stone, etc.

metal doors grained to resemble oak.

to feed grain to (an animal).

Tanning .

to remove the hair from (skins).

to soften and raise the grain of (leather). ?

against the or one's grain, in opposition to one's temper, inclination

or character

Haggling always went against her grain.

with a grain of salt. salt 1 ( def. 23 ) .