step-mother

Noun

stepmother (plural stepmothers)

1. A person or thing likened to a stereotypical stepmother, having cold, cruel, or ungenerous qualities.

   Synonyms:

   bonus mother

2. An animal, typically a bird, who raises the offspring of another animal.

   Synonyms:

   bonus mother

3. Synonym of co-mother (“the non-birth mother of a child in a lesbian couple”).

   Synonyms:

   co-mother

4. (rare) A viola, especially Viola tricolor, heartsease.
   • The second came up about ten days later in the lee of the channel marker, and it was called stepmother, or love-in-idelness.1974, Tove Jansson, translated by Thomas Teal, The Summer Book, Sort Of Books, published 2003, page 115