The Collaborative International Dictionary of English v.0.48:

Puritanize \Pu"ri*tan*ize\, v. i. [imp. & p. p. Puritanized;
   p. pr. & vb. n. Puritanizing.]
   To agree with, or teach, the doctrines of Puritans; to
   conform to the practice of Puritans. --Bp. Montagu.
   [1913 Webster]