The Collaborative International Dictionary of English v.0.48:

Pietistic \Pi`e*tis"tic\, Pietistical \Pi`e*tis"tic*al\, a.
   Of or pertaining to the Pietists; hence, in contempt,
   affectedly or demonstratively religious. --Addison.
   [1913 Webster]

WordNet (r) 3.0 (2006):

pietistical
    adj 1: of or relating to Pietism; "the Pietistic movement" [syn:
           pietistic, pietistical]
    2: excessively or hypocritically pious; "a sickening
       sanctimonious smile" [syn: holier-than-thou, pietistic,
       pietistical, pharisaic, pharisaical, sanctimonious,
       self-righteous]