\Ter"ti*ate\, v. t. [L. tertiatus, p. p. of tertiare to
do for the third time, fr. tertius the third.]
1. To do or perform for the third time. [Obs. & R.]
   --Johnson.
2. (Gun.) To examine, as the thickness of the metal at the
   muzzle of a gun; or, in general, to examine the thickness
   of, as ordnance, in order to ascertain its strength.