Bao

Bao, 宝 "treasure, precious" can also mean, with that same character, 'a costly debt [in currency or other valuables] that one owes in exchange for a big favor." To go into further detail about this usage would require discussion of certain forms of organized crime, which is not appropriate here. If an example is desired, further information might be found by researching the word "sheitou," which means "snake's head" or "professional smuggler, especially of human beings."