Did you lose that sock in the dryer, or loose it? Lose is a verb, while loose is almost always an adjective. They’re often confused because of their similar spelling.
Lose can only be used as a verb. It describes when you “come to be without something” (e.g. “to lose a sock in the laundry”) or “to suffer defeat or fail to win” (e.g. “to lose a soccer game”). Its spelling might make you think it rhymes with hose and chose, but it actually rhymes with choose and shoes. The S has a Z sound.
Loose rhymes with goose and moose, and is almost always used as an adjective. It can mean “free from restraints or binds” (e.g. “The dog runs loose in the yard”), “not bound together” (e.g. “She let her hair hang loose”), or “not fitting closely or tightly” (e.g. “The shirt was loose on me, so I bought the next size down”). It can also refer to something that isn’t very strict, or something that’s relaxed or limber.
Loosen vs. Loose
The verb form of loose is loosen, which means “to unfasten” or “to make less tight.” Loosen is a transitive verb, which means it needs to affect an object to make sense. It also shows up as part of the casual phrase “loosen up,” which also means “to relax.” Loosen is your best choice when you need a verb that represents the meaning of loose.
There’s one somewhat older use of loose as a verb that still shows up in modern English. Sometimes you may see loose being used to mean “to release” or “to set free.” For example, instead of proclaiming “Release the kraken!” when you want to set a sea monster on your enemies, you could say “Loose the kraken!” However, this is generally considered an outdated use of the word.
When you’re trying to decide between lose and loose, consider whether you’re looking for an adjective or a verb. If you’re describing something that’s free from restraints, relaxed, or not tightly fitted, use loose. If you’re talking about the action of misplacing or not winning something, use lose. Finally, if you lose a sock, it’s disappeared. If you loose a sock, you’ve set it free.