In relation to birth, a child who is born at the completion of gestation and so has had the normal amount of time to develop in the uterus, as opposed to a premature child, who is born without having the full nine months (medically, 40 weeks) to develop.
A complete pregnancy of forty weeks.
In obstetrics, an infant born between the beginning of the 38th and the end of the 41st week of gestation.