If a noise is loud, the level of sound is very high and it can be easily heard. Someone or something that is loud produces a lot of noise.

If someone is loud in their support for or criticism of something, they express their opinion very often and in a very strong way.

If you describe something, especially a piece of clothing, as loud, you dislike it because it has very bright colours or very large, bold patterns which look unpleasant.

If you tell someone something loud and clear, you are very easily understood, either because your voice is very clear or because you express yourself very clearly.

If you say or read something out loud, you say it or read it so that it can be heard, rather than just thinking it.