The term 'Boto' is pigin slang in Hawaii for the male's sexual organs. 😂🤣 After doing some research and using some common sense, I have come to a conclusion of it's origin. During our sugar cane era where we imported a lot of our labor from a lot of different countries; Japan, China, Phillipines, and even Portugal, we have taken words and slang from their cultures and made them our own. This includes the term 'boto'. 😂🤣 Boto is a dolphin from Portugal. The male organ looks like the nose of the dolphin. There you go, the origin, of our slang word. The Portuguese brought the slang word with them, and we took it and made it part of our culture.