The Collaborative International Dictionary of English v.0.48:

Romanize \Ro"man*ize\, v. t. [imp. & p. p. Romanized; p. pr. &
   vb. n. Romanizing.]
   1. To Latinize; to fill with Latin words or idioms. [R.]
      --Dryden.
      [1913 Webster]

   2. To convert to the Roman Catholic religion.
      [1913 Webster]