Describing a strict rule that cannot be altered under any circumstances. This term originally described a ship that was out of the water, either because it had run aground or because it was in dry dock, and hence could not move. In the mid-nineteenth century the term was transferred to inalterable courses of action or precepts. The OED lists an early figurative use in two different speeches given in the House of Commons in 1867: “The House has . . . determined to have no hard and fast line.”