The Collaborative International Dictionary of English v.0.48:

Waster \Wast"er\, n. [OE. wastour, OF. wasteor, gasteor. See
   Waste, v. t.]
   [1913 Webster]
   1. One who, or that which, wastes; one who squanders; one who
      consumes or expends extravagantly; a spendthrift; a
      prodigal.
      [1913 Webster]

            He also that is slothful in his work is brother to
            him that is a great waster.           --Prov. xviii.
                                                  9.
      [1913 Webster]

            Sconces are great wasters of candles. --Swift.
      [1913 Webster]

   2. An imperfection in the wick of a candle, causing it to
      waste; -- called also a thief. --Halliwell.
      [1913 Webster]

   3. A kind of cudgel; also, a blunt-edged sword used as a
      foil.
      [1913 Webster]

            Half a dozen of veneys at wasters with a good fellow
            for a broken head.                    --Beau. & Fl.
      [1913 Webster]

            Being unable to wield the intellectual arms of
            reason, they are fain to betake them unto wasters.
                                                  --Sir T.
                                                  Browne.
      [1913 Webster]

WordNet (r) 3.0 (2006):

waster
    n 1: someone who dissipates resources self-indulgently [syn:
         wastrel, waster]
    2: a person who destroys or ruins or lays waste to; "a destroyer
       of the environment"; "jealousy was his undoer"; "uprooters of
       gravestones" [syn: destroyer, ruiner, undoer, waster,
       uprooter]