Rid"er (?), n.
1.
One who, or that which, rides.
2.
Formerly, an agent who went out with samples of goods to obtain orders; a commercial traveler.
[Eng.]
3.
One who breaks or manages a horse.
Shak.
4.
An addition or amendment to a manuscript or other document, which is attached on a separate piece of paper; in legislative practice, an additional clause annexed to a bill while in course of passage; something extra or burdensome that is imposed.
After the third reading, a foolish man stood up to propose a rider.
Macaulay.
This [question] was a rider which Mab found difficult to answer.
A. S. Hardy.
5. Math.
A problem of more than usual difficulty added to another on an examination paper.
6. [D. rijder.]
A Dutch gold coin having the figure of a man on horseback stamped upon it.
His moldy money ! half a dozen riders.
J. Fletcher.
7. Mining
Rock material in a vein of ore, dividing it.
8. Shipbuilding
An interior rib occasionally fixed in a ship's hold, reaching from the keelson to the beame of the lower deck, to strengthen her frame.
Totten.
9. Naut.
The second tier of casks in a vessel's hold.
10.
A small forked weight which straddles the beam of a balance, along which it can be moved in the manner of the weight on a steelyard.
11.
A robber.
[Obs. or Prov. Eng.]
Drummond.
Rider's bone Med., a bony deposit in the muscles of the upper and inner part of the thigh, due to the pressure and irritation caused by the saddle in riding.
© Webster 1913.