n. One who backs or gets on the back: as, a backer of untamed horses.n. One who backs or supports, or who aids and abets, another in an undertaking, especially in any trial of skill, agility, or strength; also, one who bets or “lays” his money in favor of a particular person, horse, etc., in a contest; one who indorses the notes or sustains the credit of another.n. In architecture, a narrow slate laid on the back of a broad square-headed one, where the slates begin to diminish in width.n. Nautical, a strap of rope or sennit fastened to a yard-arm to secure the head-earings of a sail.Same as backermore.