poison pill: Meaning and Definition of

poi'son pill"

Pronunciation: [key]
  1. a pellet of a quick-acting poison, as cyanide, for a spy to carry in order to commit suicide when faced with capture or torture.
  2. any of various business devices created to prevent a company from being taken over by another, as issuing a new class of stock or stock warrants that would become costly to the buyer in the event of a takeover.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.