IPA: /ˈstɛpˌdeɪm/
KK: /ˈstɛpˌdeɪm/
A woman who is married to someone's father but is not their biological mother.
After her father remarried, she had to adjust to living with her stepdame.
Stepdame → The word is formed from "step" (from Old English *stæpe*, meaning a step or a degree) and "dame" (from Old French *dame*, meaning lady or woman). A stepdame refers to a woman who is a stepmother, indicating her role as a lady in relation to her partner's children from a previous relationship.
Think of a 'step' as a degree of relationship and 'dame' as a lady — a stepdame is a lady who takes a step into the role of a mother.