from The Century Dictionary and Cyclopedia
- n. In marine hardware, a brass bar in the form of a quadrant, or quarter-circle, hinged to a plate at one end and having a slot in the middle. The plate is screwed to the side of a ship's skylight and the sash carries a set-screw that slides in the slot. It is used to hold the sash open at any desired angle.
Sorry, no etymologies found.