Something that is thin is much narrower than it is long.

A person or animal that is thin has no extra fat on their body .

Something such as paper or cloth that is thin is flat and has only a very small distance between its two opposite surfaces.

Liquids that are thin are weak and watery.

A crowd or audience that is thin does not have many people in it.

A thin smile is one that is not friendly or humorous.

Thin clothes are made from light cloth and are not warm to wear.

If you describe an argument or explanation as thin, you mean that it is weak and difficult to believe.

A voice or sound that is thin is high-pitched and not very loud.

If someone's hair is described as thin, they do not have a lot of hair.

When you thin something or when it thins, it becomes less crowded because people or things have been removed from it.

To thin a sauce or liquid means to make it weaker and more watery by adding another liquid to it.

If a man's hair is thinning, it has begun to fall out.

If someone's patience, for example, is wearing thin, they are beginning to become impatient or angry with someone.