Change 1 letter to make a new word #2

Ruge

 Moonlight:

Ruge 

What is the meaning of this word, I could not find in any dictionary? Is it a slang term for something?

 Northern raveller:

What is the meaning of this word, I could not find in any dictionary? Is it a slang term for something?

Ruge is a German surname, often found in the Grand Est region of France. Notable people with the surname include: Arnold Ruge (1802-1889), German philosopher. 

 Northern raveller:

Bouge

Bouger

Buge

Mule

Full

Null