rider in Irish

(generally) Someone who rides a horse or (later) a bicycle, motorcycle etc. [from 14th c.]

(politics) A supplementary clause added to a document after drafting, especially to a bill under the consideration of a legislature. [from 17th c.]

(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. [from 17th c.]