Terceira (tĕrsā´rə), island (1991 pop. 59,248), 153 sq mi (396 sq km), in the N Atlantic, one of the central Azores, Portugal. The chief town is Angra do Heroísmo, which gives its name to the district. Grains, cattle, and embroidery are exported, and there is a growing tourist trade. There is a NATO air base there.
"Terceira." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. (March 22, 2018). http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/terceira
"Terceira." The Columbia Encyclopedia, 6th ed.. . Retrieved March 22, 2018 from Encyclopedia.com: http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/terceira