Padlock (noun)

1. A portable lock with a hinged shackle that can be passed through the staple of a hasp or the links of a chain and then snapped shut.
2. A small lock that is typically used to secure a gate or door.

Origin:

Derived from the word "pad" meaning "a flat surface" and "lock" which means "a mechanism that prevents opening".

Examples:

1. The door was secured with a padlock.
2. The gate was locked with a padlock.
3. The padlock was difficult to pick.
4. The padlock was replaced with a more secure one.
5. The padlock was small but very strong.