The term "secundines" refers to the placenta and fetal membranes that are expelled following the birth of a child. There are a few different synonyms for this term, including afterbirth, postpartum tissues, and birth waste. Each of these synonyms refers to the same thing - the tissues and structures that are no longer needed after the baby is born, and that must be expelled from the mother's body in order to complete the birthing process. While the terminology may vary slightly from one source to another, all of these synonyms refer to the same structures and tissues that are crucial to a safe and successful childbirth.