semantic class names are HTML class names deliberately chosen to reflect the meaning (semantics) of the content being marked up, rather than the presentation (style). semantic class names have been a part of a modern web design since 2002 (please research and add earlier citations if found), and are a part of the practice of semantic HTML authoring, also known as POSH.
For more on semantic class names, see:
- Use class with semantics in mind by W3C
- A Touch of Class by Tantek Çelik
- Competent Classing by Eric Meyer
- Keep Your Classes Clean
- More about the 'class' attribute by Tantek Çelik