Half a fish

• Repeated, a popular grilled fish
• Half a seafood dinner?
• When repeated, fish on a menu
• When doubled, another name for dorado
• When repeated, a dolphin
• When doubled, a Hawaiian fish
• Luau fish, for short
• Hawaiian fish, on some menus
• Hawaiian fish, for short

Wikipedia Word definitions in Wikipedia
Mahi is a name of multiple origins, found in various countries.