Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Cercīna, ae, f., = Κέρκινα, an island off the east coast of Africa, with a town of the same name, now Kerkein or Kerkena, Plin. 5, 7, 7, § 41; Auct. B. Afr. 34; Liv. 33, 48, 11; Tac. A. 1, 53; 4, 13; Dig. 1, 2, 2, § 42.
The inhabitants, Cercīnātes, Auct. B. Afr. 34.