An alternative to the title "step-mom," which is a female caregiver of a child who assumed the parental role through marriage to one of the child's original (usually biological) parents. Most commonly, a step-mom is the second wife of a child's biological father. I live with my mom during the week and then visit my dad and bonus mom every other weekend.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.