Definition of "unkindness"

unkindness

noun
countable and uncountable, plural unkindnesses
1. (uncountable) The state or quality of being unkind.
2. (countable) An unkind act.
3. (countable) The collective noun for ravens
  Quotations
  All Olwynne could remember, though, was her father falling away from her into some deep pit, his black wings bent over his face, and then hundreds of ravens, an unkindness of ravens, plummeting from the sky to peck out her eyes.
  2006, Kate Forsyth, The Shining City: Book Two of Rhiannon's Ride‎, Roc, published 2006
  "There's an unkindness of ravens that roosts on top of the guild. Their numbers are growing by the day. Aren't they spectacular?
  2007, Elizabeth Haydon, The Thief Queen's Daughter, Starscape Books, published 2007, page 228
  A raven cawed somewhere up ahead, and its cry was answered by others, an unkindness of ravens on all sides.
  2010, Rick Burroughs, Alan Wake, Tor Books, published 2010, page 38