chock

noun

• 1a wedge or block placed against a wheel or rounded object, to prevent it from moving.
• a support on which a rounded structure, such as a cask or the hull of a boat, may be placed to keep it steady.

• 2a fitting with a gap at the top, through which a rope or line is run.

verb

• prevent the forward movement of (a wheel or vehicle) with a chock.
• support (a boat, cask, etc.) on chocks.