white-knight

Noun

white knight (plural white knights)

1. An 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. A hero, savior, or righteous individual.

   Antonyms:

   black knight

3. (derogatory, figuratively) Someone 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. (Internet, derogatory, figuratively, informal) A man who defends a woman in debate etc. in an attempt to gain her favour.
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.

See all 7 meanings of white knight