clean

If something is clean, it is free from dirt

Example: The kids came back from the washroom with clean hands and faces.

If a technology is clean, it doesn't produce much pollution.

Example: We want to use wind as safe, clean, non-polluting energy.

If something is clean, it is not bad.

Example: There was a lot of pushing in their last game, but today's match was mostly clean.

A clean piece of paper, start, etc. has nothing from before: no writing, no history, etc.

Example: Why don't you get a clean piece of paper and start over.

If a something is clean, it is smooth, simple, and regular, without anything unwanted.

Example: Your company website needs a clean design that makes it easy for consumers to understand what you're selling.