bonanza /bə-nanˈzə or bəʊ- or bo-/

1. A rich mine or vein of precious ore (N American)
2. A large amount of (usu) silver
3. Any source of wealth or stroke of luck

Very prosperous

• unornamented
• unorthodox
• unorthodoxies
• unorthodoxly
• unorthodoxy
• unossified
• unostentatious
• unostentatiously
• unostentatiousness
• unovercome
• unoverthrown
• unowed
• unowned
• unoxidised
• unoxidized
• unpaced
• unpacified
• unpack
• unpacked
• unpacker
• unpackers
• unpacking
• utu
• U-tube
• U-tubes