What is an aitch?

The word "aitch" can refer to a couple of things, depending on the context:

1. The letter "H": This is the most common meaning. The letter "H" is sometimes called "aitch" in pronunciation.

2. A small island in a river: This is a less common usage, primarily found in some dialects of English, particularly in the UK.

It's important to consider the context to determine the correct meaning of "aitch."