rider

Etymology

From Middle English ryder, ridere, from Late Old English rīdere (“rider, knight”); equivalent to ride + -er. Compare Dutch rijder, German Reiter.

noun

1. A mounted person.
   1. (now archaic or historical) A knight, or other mounted warrior.
   2. An old Dutch gold coin with the figure of a man on horseback stamped upon it.
   3. (generally) Someone who rides a horse or (later) a bicycle, motorcycle etc.
   4. (now historical or archaic) A mounted robber; a bandit, especially in the Scottish borders.
      In Evosdale eight and fourty notorious Riders are hung on growing Trees, the most famous of which was John Arm-Strong 1655, William Drummond of Hawthornden, History of Scotland[…]
   5. (obsolete) Someone who breaks in or manages a horse; a riding master.
   6. (now rare, historical) An agent who goes out with samples of goods to obtain orders; a commercial traveller or travelling salesman.
      I set out with a Paisley manufacturer and a London rider, the latter of whom I envied for his smartness and self-complacency. 1790, James Boswell, in Danziger & Brady (eds.), Boswell: The Great Biographer (Journal 1789–1795), Yale 1989, p. 70
   7. (now chiefly US) Someone riding in a vehicle; a passenger on public transport.
      On the London Underground, Piccadilly Circus station is nearly vacant on a weekday morning, while the Delhi Metro is ferrying fewer than half of the riders it used to. 2021-03-25, Somini Sengupta, Geneva Abdul, Manuela Andreoni, Veronica Penney, “Riders Are Abandoning Buses and Trains. That's a Problem for Climate Change.”, in The New York Times, →ISSN
2. An addition, supplement.
   1. (politics) A supplementary clause added to a document after drafting, especially to a bill under the consideration of a legislature.
   2. An amendment or addition to an entertainer's performance contract, often covering a performer's equipment or food, drinks, and general comfort requirements.
   3. An additional matter or question arising in corollary; a qualification.
      But they would hush momentarily for the farce, specially if billed with the grand rider: 'licensed by the Lord Chamberlain expressly for this theatre'. 2015, Ed Glinert, East End Chronicles, Penguin UK
   4. A supplementary question, now especially in mathematics.
      This [question] was a rider which Mab found difficult to answer. 1886, Arthur Sherburne Hardy, The Wind of Destiny
3. Technical senses.
   1. (shipbuilding) An interior rib occasionally fixed in a ship's hold, reaching from the keelson to the beams of the lower deck, to strengthen the frame.
      During the four weeks of research, a considerable part of the ships structure was discovered underneath the ballast stones: keel, floor timbers, strakes, keelson together with mast step and its sisters and rider 2016, Lucy Blue, Frederick M. Hocker, Anton Englert, Connected by the Sea
   2. (mining, now rare) Rock material in a vein of ore, dividing it.
   3. (nautical, in the plural) The second tier of casks in a vessel's hold.
   4. A small, sliding piece of thin metal on a balance, used to determine small weights.
   5. (cartomancy) The first Lenormand card, also known as either the horseman or the cavalier.
   6. (chess) A piece, such as the rook or bishop, which moves any distance in one direction, as long as no other piece is in the way.