The Collaborative International Dictionary of English v.0.48:

Augustine \Au*gus"tine\, Augustinian \Au`gus*tin"i*an\, n.
   (Eccl.)
   A member of one of the religious orders called after St.
   Augustine; an Austin friar.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Augustine
    n 1: (Roman Catholic Church) one of the great Fathers of the
         early Christian church; after a dramatic conversion to
         Christianity he became bishop of Hippo Regius in North
         Africa; St. Augustine emphasized man's need for grace
         (354-430) [syn: Augustine, Saint Augustine, St.
         Augustine, Augustine of Hippo]