Pietist \Pi"e*tist\, n. [Cf. G. pietist, F. pi['e]tiste. See {Piety}.] (Eccl. Hist.) One of a class of religious reformers in Germany in the 17th century who sought to revive declining piety in the Protestant churches; -- often applied as a term of reproach to those who make a display of religious feeling. Also used adjectively. [1913 Webster] Pietistic