Английский Этимологический словарь - stud (2)

- "horse used for breeding," O.E. stod "place where horses are kept for breeding," from P.Gmc. *stodo; related to O.E. standan (see stand). Sense of "male horse kept for breeding" is first recorded 1803; meaning "man who is highly active and proficient sexually" is late 19c.; that of "any young man" is from 1929.