The Collaborative International Dictionary of English v.0.48:

Senseless \Sense"less\, a.
   Destitute of, deficient in, or contrary to, sense; without
   sensibility or feeling; unconscious; stupid; foolish; unwise;
   unreasonable.
   [1913 Webster]

         You blocks, you stones, you worse than senseless
         things.                                  --Shak.
   [1913 Webster]

         The ears are senseless that should give us hearing.
                                                  --Shak.
   [1913 Webster]

         The senseless grave feels not your pious sorrows.
                                                  --Rowe.
   [1913 Webster]

         They were a senseless, stupid race.      --Swift.
   [1913 Webster]

         They would repent this their senseless perverseness
         when it would be too late.               --Clarendon.
   [1913 Webster] -- Sense"less*ly, adv. -- Sense"less*ness,
   n.
   [1913 Webster]

WordNet (r) 3.0 (2006):

senselessness
    n 1: total lack of meaning or ideas [syn: inanity,
         senselessness, mindlessness, vacuity,
         pointlessness]