The term 'Yellow Fin Tuna' refers to a species of tuna found in tropical and subtropical oceans worldwide. The scientific name for this species is Thunnus albacares, and it is commonly referred to as AHI, which is the three-letter solution to the crossword. Yellow Fin Tuna is a popular food fish, and is highly sought after for its flavor and texture. It is also a popular game fish, and is often used for sport fishing.