RI'DER, noun
1. One who is borne on a horse or other beast, or in a vehicle.
2. One who breaks or manages a horse.
3. The matrix of an ore.
4. An inserted leaf or an additional clause, as to a bill in parliament.
5. In ship building, a short of interior rib fixed occasionally in a ships's hold, opposite to some of the timbers to which they are bolted, and reaching from the keelson to the beams of the lower deck, to strengthen her frame.