Source : Webster's Revised Unabridged Dictionary (1913)

Senseless \Sense"less\, a.
   Destitute of, deficient in, or contrary to, sense; without
   sensibility or feeling; unconscious; stupid; foolish; unwise;
   unreasonable.

         You blocks, you stones, you worse than senseless
         things.                                  --Shak.

         The ears are senseless that should give us hearing.
                                                  --Shak.

         The senseless grave feels not your pious sorrows.
                                                  --Rowe.

         They were a senseless, stupid race.      --Swift.

         They would repent this their senseless perverseness
         when it would be too late.               --Clarendon.
   --- {Sense"less*ly}, adv. -- {Sense"less*ness}, n.

Source : WordNet®

senseless
     adj 1: not marked by the use of reason; "mindless violence";
            "reasonless hostility"; "a senseless act" [syn: {mindless},
             {reasonless}]
     2: unresponsive to stimulation; "he lay insensible where he had
        fallen"; "drugged and senseless" [syn: {insensible}]
     3: lacking import; "a pointless remark"; "a life essentially
        purposeless"; "senseless violence" [syn: {pointless}, {purposeless}]
     4: (of especially persons) lacking sense or understanding or
        judgment [syn: {nitwitted}, {soft-witted}, {witless}]