Definition of rider

• n. - One who, or that which, rides.
• n. - Formerly, an agent who went out with samples of goods to obtain orders; a commercial traveler.
• n. - One who breaks or manages a horse.
• n. - 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.
• n. - A problem of more than usual difficulty added to another on an examination paper.
• n. - A Dutch gold coin having the figure of a man on horseback stamped upon it.
• n. - Rock material in a vein of ore, dividing it.
• n. - An interior rib occasionally fixed in a ship's hold, reaching from the keelson to the beams of the lower deck, to strengthen her frame.
• n. - The second tier of casks in a vessel's hold.
• n. - 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.
• n. - A robber.