WordNet (r) 3.0 (2006):

city father
    n 1: an important municipal official

Moby Thesaurus II by Grady Ward, 1.0:

54 Moby Thesaurus words for "city father":
   MP, Member of Congress, Member of Parliament, alderman, archon,
   assemblyman, bailie, burghermaster, burgomaster, cabinet member,
   cabinet minister, chancellor, chosen freeholder, city councilman,
   city manager, commissar, commissioner, congressman, congresswoman,
   councillor, councilman, councilwoman, county commissioner,
   county supervisor, elder, floor leader, headman, induna, lawgiver,
   lawmaker, legislator, lord mayor, magistrate, maire,
   majority leader, mayor, minister, minister of state,
   minority leader, party whip, portreeve, reeve, representative,
   secretary, secretary of state, selectman, senator, solon,
   state senator, supervisor, syndic, undersecretary, warden, whip