noun: a baby that is born through the anal cavity nine months after its mother received anal penetration. Often brown in color. The mother often times will develop a hunchback in the late stages of pregnancy.
Nurse: "Congratulations! It's a back baby"
by HelloJudsudb;sdjbdwj March 16, 2009
1 more definition
what would happen if a gay guy got pregnant.
So you two guys have been together for a while; when's one of you gonna pop out a back-baby and settle down.
by chris666fuckyoufortakingthisnamealready October 10, 2006