The Collaborative International Dictionary of English v.0.48:
Priggish \Prig"gish\, a. Like a prig; conceited; pragmatical. -- Prig"gish*ly, adv. -- Prig"gish-ness, n. [1913 Webster]WordNet (r) 3.0 (2006):
priggishly adv 1: in a priggish manner; "this professor acts so priggishly --like a moderator with a gavel!"