What does the word checkmate mean?

Usage examples for checkmate

  1. They are as injurious as they are false, and they will checkmate the progress of any man or of any people that believes them. – Emerson and Other Essays by John Jay Chapman
  2. Grosvenor considered this a dangerous combination and said that steps should be taken to checkmate it at once. – The Life of Lyman Trumbull by Horace White