1. To do something you don't want others to know about or what you shouldn't be doing, e.g., selling illicit drugs, assaulting others. A code phrase for being involved with some criminal activity.
2. To associate with people your friends and family regard as undesirable or beneath your dignity.
3. To take care of important business.
1. You gotta do what you gotta do to survive because there are no jobs available.
2. I know my friends think my boyfriend's no good, but I'm doing what I gotta do.
3. I'm doing what I gotta do to get something to eat.
what you say when you see a duck, see someone murdering a duck, currently murdering the duck yourself or when you are eating a duck. Only the coolest people know this great saying by the Red Ducks
*sees someone eating a duck"
"a mans gotta eat, a ducks gotta die"
"your quite correct, the duck is dead; I am eating it"