grain

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A small, dry, one-seeded fruit of a cereal grass, having the fruit and the seed walls united.
• noun The fruits of cereal grasses especially after having been harvested, considered as a group.
• noun A cereal grass.
• noun Cereal grasses considered as a group.
• noun A relatively small discrete particulate or crystalline mass.
• noun A small amount or the smallest amount possible.
• noun Aerospace A mass of solid propellant.
• noun A unit of weight in the US Customary System, an avoirdupois unit equal to 0.002285 ounce (0.065 gram).
• noun The arrangement, direction, or pattern of the fibrous tissue in wood.
• noun The side of a hide or piece of leather from which the hair or fur has been removed.
• noun The pattern or markings on this side of leather.
• noun The pattern produced, as in stone, by the arrangement of particulate constituents.
• noun The relative size of the particles composing a substance or pattern.
• noun A painted, stamped, or printed design that imitates the pattern found in wood, leather, or stone.
• noun The direction or texture of fibers in a woven fabric.
• noun A state of fine crystallization.
• noun Basic temperament or nature; disposition.
• noun An essential quality or characteristic.
• noun Archaic Color; tint.
• intransitive verb To cause to form into grains; granulate.
• intransitive verb To paint, stamp, or print with a design imitating the grain of wood, leather, or stone.
• intransitive verb To give a granular or rough texture to.
• intransitive verb To remove the hair or fur from (hides) in preparation for tanning.
• intransitive verb To form grains.
• idiom (against the grain) Contrary to custom, one's inclination, or good sense.
• idiom (with a grain of salt) With reservations; skeptically.

from The Century Dictionary.

• noun A dialectal (Scotch) form of groan.
• noun A small hard, seed; specifically, a seed of one of the cereal plants, wheat, rye, oats, barley, maize, or millet; a corn.
• noun Collectively, corn in general; the gathered seeds of cereal plants in mass; also, the plants themselves, whether standing or gathered: as, to grind or thresh grain; a field or a stack of grain.
• noun The smallest unit of weight in most systems, originally determined by the weight of a plump grain of wheat.
• noun Any small hard particle, as of sand, gunpowder, sugar, salt, etc.; hence, a minute portion of anything; the smallest amount of anything: as, he has not a grain of wit.
• noun In botany, a grain-like prominence or tubercle, as upon the sepals of dock.
• noun plural The husks or remains of malt after brewing, or of any grain after distillation.
• noun The quality of a substance due to the size, character, or arrangement of its grains or particles, as its coarseness or fineness, or superficial roughness or smoothness; granular texture: as, a stone or salt of coarse grain; marble or sugar of fine grain.
• noun Fibrous texture or constitution, especially of wood; the substance of wood as modified by the quality, arrangement, or direction of its fibers: as, boxwood has a very compact grain; wood of a gnarled grain; to plane wood with, against, or across the grain.
• noun Hence Intimate structure or character; intrinsic or essential quality.
• noun A spice: same as grains of paradise (which see, below).
• noun One of the grain-like insects of the genus Coccus, as C. polonicus or C. ilicis, which yield a scarlet dye; later, especially, cochineal; the product of the Coccus cacti; kermes: so called from the granular appearance of the dried insects. See cut under cochineal. Hence — A red-colored dye; a red color of any kind pervading the texture: sometimes used as equivalent to Tyrian purple, Any fast color. See in grain, below.
• noun The side of leather from which the hair has been removed, showing the fibrous texture.
• noun In mining, cleat or cleavage.
• noun plural A solution of birds' dung used in leather-manu facture to counteract the effects of lime and make the leather soft and flexible.
• noun With the soarlet dye obtained from insects of the genus Coccus.
• noun With any fast dye; in fast colors: as, to dye in grain.
• noun See def. 9.
• noun In the tobacco industry, a deposit of calcium oxalate, in scattered globules, often at the base of the hairs, formed upon tobacco-leaves in the process of curing and sweating.