The Collaborative International Dictionary of English v.0.48:

Benumb \Be*numb"\, v. t. [imp. & p. p. Benumbed; p. pr. & vb.
   n. Benumbing.] [OE. binomen, p. p. of binimen to take away,
   AS. beniman; pref. be + niman to take. See Numb, a., and
   cf. Benim.]
   To make torpid; to deprive of sensation or sensibility; to
   stupefy; as, a hand or foot benumbed by cold.
   [1913 Webster]

         The creeping death benumbed her senses first. --Dryden.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Benumbed \Be*numbed"\, a.
   Made torpid; numbed; stupefied; deadened; as, a benumbed body
   and mind. -- Be*numbed"ness, n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

benumbed
    adj 1: lacking sensation; "my foot is asleep"; "numb with cold"
           [syn: asleep(p), benumbed, numb]
    2: having lost or been caused to lose interest because of
       overexposure; "the mind of the audience is becoming dulled";
       "the benumbed intellectual faculties can no longer respond"
       [syn: dulled, benumbed]

Moby Thesaurus II by Grady Ward, 1.0:

91 Moby Thesaurus words for "benumbed":
   Laodicean, Olympian, aloof, anesthetized, apathetic, asleep, blah,
   blase, bored, callous, comatose, dead, deadened, debilitated,
   desensitized, detached, disinterested, dopey, dormant, droopy,
   drugged, dull, enervated, exanimate, heartless, heavy,
   hebetudinous, hopeless, impassible, imperceptive, impercipient,
   in a stupor, inanimate, indifferent, inert, insensate, insensible,
   insensitive, insentient, insouciant, jaded, lackadaisical, languid,
   languorous, leaden, lethargic, lifeless, listless, lumpish,
   moribund, nonchalant, numb, numbed, obdurate, obtuse, passive,
   phlegmatic, pluckless, pooped, resigned, sated, senseless, slack,
   sleepy, slow, sluggish, somnolent, soporific, spiritless,
   spunkless, stagnant, stagnating, stoic, stultified, stupefied,
   supine, thick-skinned, thick-witted, torpid, uncaring, unconcerned,
   unfeeling, unfelt, uninterested, unperceptive, vegetable,
   vegetative, wan, weary, withdrawn, world-weary