- grain
- c.1200, from O.Fr. grein, from L. granum "seed" (see corn). As collective sing. meaning "seed of wheat and allied grasses used as food," it is attested from early 14c. Extended in M.E. to other objects (e.g. salt, sand). Used of wood (1560s), from the arrangement of fibers, which resemble seeds. Hence, against the grain (1650), a metaphor from carpentry: cutting across the fibers of the wood is more difficult than cutting along them.