The Collaborative International Dictionary of English v.0.48:

Prudery \Prud"er*y\, n.; pl. Pruderies. [F. pruderie. See
   Prude.]
   The quality or state of being prudish; excessive or affected
   scrupulousness in speech or conduct; stiffness; coyness.
   --Cowper.
   [1913 Webster]

WordNet (r) 3.0 (2006):

prudery
    n 1: excessive or affected modesty [syn: primness,
         prudishness, prudery, Grundyism]