The Collaborative International Dictionary of English v.0.48:

dignitary \dig"ni*ta*ry\, n.; pl. dignitaries. [Cf. F.
   dignitaire, fr. L. dignitas.]
   One who possesses exalted rank or holds a position of dignity
   or honor; especially, one who holds an ecclesiastical rank
   above that of a parochial priest or clergyman.
   [1913 Webster]

WordNet (r) 3.0 (2006):

dignitary
    n 1: an important or influential (and often overbearing) person
         [syn: very important person, VIP, high-up,
         dignitary, panjandrum, high muckamuck]