WordNet (r) 3.0 (2006):

polish off
    v 1: finish a task completely; "I finally got through this
         homework assignment" [syn: get through, wrap up,
         finish off, mop up, polish off, clear up, finish
         up]
    2: kill intentionally and with premeditation; "The mafia boss
       ordered his enemies murdered" [syn: murder, slay, hit,
       dispatch, bump off, off, polish off, remove]
    3: finish eating all the food on one's plate or on the table;
       "She polished off the remaining potatoes" [syn: eat up,
       finish, polish off]

Moby Thesaurus II by Grady Ward, 1.0:

75 Moby Thesaurus words for "polish off":
   KO, accomplish, achieve, attain, blast, blot out, bump off,
   call off, cancel, compass, complete, consummate, croak, deal with,
   delete, discharge, dispatch, dispose of, do, do in, do the job,
   do the trick, drop the curtain, effect, effectuate, enact, end off,
   erase, execute, expunge, extinguish, fetch, finalize, finish, fix,
   fold up, fulfill, get, get it over, get over with,
   get through with, give the business, give the quietus, gun down,
   hit, ice, kayo, kibosh, kill, knock off, knock out, lay out, make,
   manage, off, perfect, perform, produce, punish, put, put away,
   put paid to, realize, rub out, scrag, settle, shoot down, succeed,
   take care of, turn the trick, waste, wipe out, work, work out,
   zap