grain (Noun) — A relatively small granular particle of a substance. ex. "a grain of sand" ex. "a grain of sugar"
grain (Noun) — Foodstuff prepared from the starchy grains of cereal grasses.
grain (Noun) — The side of leather from which the hair has been removed.
grain (Noun) — A weight unit used for pearls or diamonds: 50 mg or 1/4 carat.
grain (Noun) — 1/60 dram; equals an avoirdupois grain or 64.799 milligrams.
grain (Noun) — 1/7000 pound; equals a troy grain or 64.799 milligrams.
grain (Noun) — Dry seed-like fruit produced by the cereal grasses: e.g. wheat, barley, Indian corn.
grain (Noun) — A cereal grass. ex. "wheat is a grain that is grown in Kansas"
grain (Noun) — The smallest possible unit of anything. ex. "there was a grain of truth in what he said" ex. "he does not have a grain of sense"
grain (Noun) — The direction, texture, or pattern of fibers found in wood or leather or stone or in a woven fabric. ex. "saw the board across the grain"
grain (Noun) — The physical composition of something (especially with respect to the size and shape of the small constituents of a substance). ex. "sand of a fine grain" ex. "a stone of coarse grain"
grain (Verb) — Thoroughly work in. ex. "His hands were grained with dirt"
grain (Verb) — Paint (a surface) to make it look like stone or wood.
grain (Verb) — Form into grains.
grain (Verb) — Become granular.