n. The biological mother of an adopted child.
Also Seen As
Elizabeth Church, a psychologist and professor at Mount Saint Vincent University in Halifax and author of Understanding Stepmothers, says that in films and literature, "the only good stepmother was almost a servant."

Well, that makes sense to anyone who has stepmothered. Biomom gets all the credit, homemade cards and breakfast in bed. Smom — a word for stepmom that sounds appropriately beleaguered — gets to do another load of laundry.
—Sarah Hampson, “Happy under-appreciation day: Celebrating the stepmom,” The Globe and Mail, May 08, 2008
To lose a parent may be regarded as a misfortune; to lose and find a mother in the same week looks downright irresponsible.

But this is the predicament of April Epner, unassuming grade-school teacher, age 39. No sooner does April's adoptive mother pass away than her bio-mom comes forward.
—Carrie Rickey, “Mother-daughterhood movie tests limits of maternal bond,” The Philadelphia Inquirer, May 02, 2008
1987 (earliest)
She has a place in our lives but it doesn't happen to be at our dinner table. Someday, he may want to go find her. She is, after all, his biological mother. Bio moms we call them in adoption circles.
—Jane Leavy, “My Baby and Baby M,” The Washington Post, March 22, 1987