What does the word Subtility mean?

Usage examples for Subtility

  1. The troops which are now approaching have been for years inured to the practice of slaughter; they join to a courage which defies every danger, a knowledge of every fraud and subtility which can confound or baffle an adversary. – The History of Sandford and Merton by Thomas Day
  2. The prudence of the man of action and the administrator balanced his outbursts of dialectical subtility, often carried too far. – Saint Augustin by Louis Bertrand