Blocks made of either wood, plastic or metal, used to keep a parked aircraft in position
Any fitting or fixture used to restrict movement, especially movement of a line; traditionally was a fixture near a bulwark with two horns pointing towards each other, with a gap between where the line can be inserted
(Otomotiv) A small block that is used to block a wheel from rolling. This keeps the vehicle from moving while working underneath it
a block of wood used to prevent the sliding or rolling of a heavy object support on chocks; "chock the boat" secure with chocks as completely as possible; "it was chock-a-block full