The Collaborative International Dictionary of English v.0.48:

Jeronymite \Je*ron"y*mite\, n. (Eccl. Hist.)
   One belonging of the medi[ae]val religious orders called
   Hermits of St. Jerome. [Written also Hieronymite.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Hieronymite \Hi`er*on"y*mite\, n. [From St. Hieronymus, or
   Jerome.] (Eccl.)
   See Jeronymite.
   [1913 Webster]