The Collaborative International Dictionary of English v.0.48:

Functionary \Func"tion*a*ry\, n.; pl. Functionaries. [Cf. F.
   fonctionnaire.]
   One charged with the performance of a function or office; as,
   a public functionary; secular functionaries.
   [1913 Webster]

WordNet (r) 3.0 (2006):

functionary
    n 1: a worker who holds or is invested with an office [syn:
         official, functionary]