white knight

plural white knights · alternative white-knight · alternative whiteknight

1. businessAn individual or corporation that intends to acquire another company in order to avert a hostile takeover.

   Forget about one possible white knight for Potash. Vale, the big Brazilian mining company, denied on Monday afternoon that it was in talks to acquire the giant Canadian fertilizer company.

   2010 August 23, “Vale Denies It Is Potash's White Knight”, in NY Times DealBook

2. fictionA hero, savior, or righteous individual.

   Antonyms: black knight

3. derogatoryfigurativelySomeone who unnecessarily defends someone else.

   After hearing her version of events, Lt. Wright assumed the role of white knight. He demanded that she file a formal complaint. She demurred, so the next day, over her objection, he alerted the academy.

   2013 July 26, James Taranto, “A Strange Sort of Justice at West Point”, in The Wall Street Journal

   1. InternetderogatoryfigurativelyinformalA man who defends a woman in debate etc. in an attempt to gain her favour.

      Synonyms: doormat, simp

4. A mushroom of species Tricholoma album.
5. Used other than figuratively or idiomatically: see white, knight.

   The white knight is attacking the pawn on e4.

present singular third person white knights · participle present white knighting · participle past white knighted · past white knighted · alternative white-knight · alternative whiteknight

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