a. and sb. [f. TER- + CENTENNIAL.] a. adj. Of or belonging to a period of three hundred years; of three hundred years’ standing; of or relating to the three-hundredth anniversary. b. sb. The three-hundredth anniversary of an event; a tercentenary.
1835. Amer. Mag., II. 151/1. The 4th of October completed three centuries since the first English Bible was printed…. This ter-centennial period was duly celebrated in England.
1882–3. Schaff’s Encycl. Relig. Knowl., III. 2007. The third tercentennial jubilee of the Reformation (1817), marks a return to the doctrines and principles of the Reformers.
1884. Lit. World (U. S.), 23 Feb., 58/2. The forthcoming celebration of the ter-centennial of the University of Edinburgh.
