The Collaborative International Dictionary of English v.0.48:

Doyen \Doy`en"\ (dw[aum]`y[aum]N"), n. [F. See Dean.]
   Lit., a dean; the senior member of a body or group; as, the
   doyen of French physicians. "This doyen of newspapers." --A.
   R. Colquhoun.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

doyen
    n 1: a man who is the senior member of a group; "he is the dean
         of foreign correspondents" [syn: dean, doyen]

Moby Thesaurus II by Grady Ward, 1.0:

32 Moby Thesaurus words for "doyen":
   artist, authority, bell cow, bellwether, chief, dean, doyenne,
   elder, eldest, father, first-born, firstling, guide, high priest,
   important person, kingfish, kingpin, lead, leader, master, maven,
   older, oldest, personage, pilot, principal, proficient, senior,
   sire, superior, top dog, virtuoso