Source : Webster's Revised Unabridged Dictionary (1913)

Sear \Sear\, n. [F. serre a grasp, pressing, fr. L. sera. See
   {Serry}.]
   The catch in a gunlock by which the hammer is held cocked or
   half cocked.

   {Sear spring}, the spring which causes the sear to catch in
      the notches by which the hammer is held.