TERCEIRA, an island in the Atlantic Ocean, belonging to Portugal, and forming part of the Azores archipelago. Pop. (1900) 48,770; area, 224 sq. m. Terceira, i.e. “ the third,” was so called as being the third island of the archipelago to be discovered by the Portuguese. From its central position it was long the seat of administration, but its capital, Angra (q.v.) or Angra do Heroismo (pop. 10,788), has lost much of its cornmercial importance. The other chief towns are Ribeirinha (3090), and Praia da Victoria (3236). Unlike the neighbouring islands, Terceira exhibits few extensive traces of volcanic action; and the summits of its mountains are generally level. It abounds in grain and cattle; but the wines are inferior, and fruits are raised merely for internal consumption. (See also Azores.)