The Collaborative International Dictionary of English v.0.48:

Flunky \Flun"ky\ (fl[u^][ng]"k[y^]), n.; pl. Flunkies
   (fl[u^][ng]"k[i^]z). [Prob. fr. or akin to flank.] [Written
   also flunkey.]
   1. A contemptuous name for a liveried servant or a footman.
      [1913 Webster]

   2. One who is obsequious or cringing; a snob.
      [1913 Webster]

   3. One easily deceived in buying stocks; an inexperienced and
      unwary jobber. [Cant, U.S.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

flunky
    n 1: a male servant (especially a footman) [syn: lackey,
         flunky, flunkey]
    2: a person of unquestioning obedience [syn: flunky,
       flunkey, stooge, yes-man]

Moby Thesaurus II by Grady Ward, 1.0:

146 Moby Thesaurus words for "flunky":
   adherent, appendage, apple-polisher, ass-licker, attendant,
   backscratcher, backslapper, blue-collar worker, bootlick,
   bootlicker, breadwinner, brown-nose, brownie, buff, casual,
   casual laborer, cavaliere servente, clawback, cog, common laborer,
   commonality, commonalty, courtier, creature, cringer, dangler,
   day laborer, dependent, disciple, dummy, dupe, employee,
   factory worker, fan, fawner, feudatory, figurehead, flatterer,
   follower, following, footlicker, footman, free lance, free-lancer,
   full-time worker, gillie, goon, groveler, hand, handshaker,
   hanger-on, helot, henchman, hoi polloi, homager, homme de cour,
   industrial worker, inferior, instrument, jackal, jobber, jobholder,
   junior, kowtower, laborer, laboring man, lackey, led captain,
   lickspit, lickspittle, liege, liege man, lightweight,
   liveried servant, lower class, lower orders, man, masses,
   mealymouth, menial, migrant, minion, moiler, myrmidon, navvy,
   office temporary, parasite, partisan, pawn, peon, proletarian,
   public, puppet, pursuer, pursuivant, retainer, roustabout,
   salaried worker, satellite, second fiddle, secondary, sectary,
   self-employed person, serf, servant, shadow, slave, spaniel, stiff,
   stooge, subaltern, subordinate, successor, suck, supporter,
   sycophant, tagtail, tail, temporary, third stringer, thug,
   timeserver, toad, toady, toiler, tool, trainbearer, truckler,
   tufthunter, underling, understrapper, vassal, votary, wage earner,
   wage slave, wageworker, ward heeler, worker, workgirl, workhand,
   working girl, workingman, workingwoman, workman, yeoman, yes-man