white knight

Meanings

1. An individual or corporation that intends to acquire another company in order to avert a hostile takeover.
2. A hero, savior, or righteous individual.
3. Someone who unnecessarily defends someone else.
4. A man who defends a woman in debate etc. in an attempt to gain her favour.
5. A mushroom of species Tricholoma album.
6. Used other than figuratively or idiomatically: see white, knight.

1. To unnecessarily defend someone, especially in an attempt to gain favour.