Loosen (verb)

1. Make (something) less tight or firm.
2. Become less tight or firm.

Origin:

Old english losnian ‘unbind, release’ (see loose).

Examples:

1. You need to loosen the screws before you can remove the cover.
2. I always have to loosen my belt after a big meal.
3. The mechanic loosened the lug nuts before changing the tire.
4. If you don't loosen up, you'll never be able to touch your toes.
5. The soil had finally loosened after the rain.