rooter

from WordNet (r) 3.0 (2006)

rooter
    n 1: an enthusiastic devotee of sports [syn: {sports fan},
         {fan}, {rooter}]

from The Collaborative International Dictionary of English v.0.48

Rooter \Rooter\, n.
   1. One who, or that which, roots; one that tears up by the
      roots.
      [1913 Webster]

   2. One who roots, or applauds. [Slang, U. S.]
      [Webster 1913 Suppl.]

from Moby Thesaurus II by Grady Ward, 1.0

32 Moby Thesaurus words for "rooter":
      adherent, admirer, amateur, applauder, appreciator, booster, buff,
      claqueur, collector, commender, devotee, dilettante, encomiast,
      eulogist, eulogizer, extoller, fan, fancier, follower, groupie,
      idolater, idolizer, lauder, panegyrist, plugger, praiser, promoter,
      puffer, tout, touter, votary, worshiper

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