A (usually) metal fastener consisting of a cylindrical body that is threaded, with a larger head on one end. It can be inserted into an unthreaded hole up to the head, with a nut then threaded on the other end; a heavy machine screw.

A sliding pin or bar in a lock or latch mechanism.

A bar of wood or metal dropped in horizontal hooks on a door and adjoining wall or between the two sides of a double door, to prevent the door(s) from being forced open.

To connect or assemble pieces using a bolt.

“Bolt the vice to the bench.”

To secure a door by locking or barring it.

“Bolt the door.”

To flee, to depart, to accelerate suddenly.

“Seeing the snake, the horse bolted.”

Suddenly; straight; unbendingly.

“The soldiers stood bolt upright for inspection.”