debilitative

from WordNet (r) 3.0 (2006)

debilitative
    adj 1: causing debilitation [syn: {debilitative}, {enervating},
           {enfeebling}, {weakening}]

from The Collaborative International Dictionary of English v.0.48

debilitative \debilitative\ adj.
   causing weakness. [Narrower terms: {debilitating (vs.
   invigorating)}]

   Syn: enervating, enfeebling, weakening.
        [WordNet 1.5]