Webster's Revised Unabridged Dictionary · 1913

Tertiate

Tertiate , transitive verb

[Latin tertiatus, past participle of tertiare to do for the third time, from tertius the third.]

1.
To do or perform for the third time. [Obsolete & Rare] — Johnson
2.
(Gunnery) 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.