to put something across a path or opening so that nothing can pass
A parked truck blocked the narrow bridge.
Please don't block the fire exit.
to stop something from happening or developing
The council voted to block the new law.
Sunscreen helps block harmful UV rays.
to stop someone from contacting you on the internet or phone
She blocked him on social media after the argument.
If you keep getting spam calls, you can block the number.
to fasten something with a lock so it cannot be opened without a key, code, or similar method
Please lock the front door before you go to bed.
She always locks her computer screen when she steps away from her desk.
✦ Old English locian ‘to close, lock’, originally ‘to fasten’.
to become fixed, stuck, or unable to move or change
The wheels can lock if you brake too hard on ice.
The file will lock once it is opened by another user.
✦ Metaphorical extension from ‘fasten’ to ‘become immovable’ first noted in the 18th century.
to hit someone hard, especially in the face, usually suddenly
The boxer suddenly clocked his opponent with a right hook.
After being insulted, Jenna clocked the rude stranger in the jaw.
✦ 20th-century slang, possibly from the idea of striking as hard as a clock’s hammer hits its bell.
