Opeth =?

because I don't think that gives the meaning of opeth.

Yes it does !!

from Opeth.com

"David had formed the band together with some bums from Täby. The name was taken from a book by author Wilbur Smith, and was originally spelledOpet without the "h" at the end. The meaning was unknown for me until I quite recently found the book myself, and got the knowledge that Opeth is the city of the moon. "