What is the meaning of Uber-?

Super; really; mega-.

The Weekend Australian. "Payne hopes for Uber-horse - Gelding fashionably attired for $3m race". Pg. 80. April 3, 2004.

Albuquerque Journal. "This Is No Place For Noise." Pg. B1. January 11, 2004.

Source: wiktionary.org