Lewis & Short

Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.

Arginūsae or Arginussae, ārum, f., = Ἀργινοῦσαι or Ἀργινοῦσσαι, three small islands in the Ægean Sea, near Lesbos: classem ab Arginusis removere, Cic. Off. 1, 24, 84 B. and K.: Arginussae ab Aege IIII. M. passuum distant, Plin. 5, 31, 39, § 140 Jan.
And in sing.: circa Arginussam, Plin. 8, 58, 83, § 225.