1. A woman who marries someone who has children who are in her same age group, yet insists on condesending labels such as "son" or "daughter" when introducing her new relatives.
2. sounds like step-monster.
3. a cross between mother and sister
4. someone who is the same age or younger than you who controls your dad, especially, if they do and say tacky things when he is not around.
My step-moster was running around the house in her underware again...