From BiblePortal Wikipedia

Webster's Dictionary [1]

(n.) A superior wine, white and red, from Constantia, in Cape Colony.

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [2]

sister of the emperor Constantine the Great, and wife of the emperor Licinius, was the patroness of Eusebius of Ceasarea and of Arius. She is said to have imbibed the views of the latter at least, through her influence the emperor Constantine was led to invite Arius to his court, where he soon established an exclusive influence (Robertson, Hist. of the Christ. Church, book 2, chapter 1; Ceillier, 3:250, 417).

The Nuttall Encyclopedia [3]

A wine district of Cape Colony under E. flank of Table Mountain.