adj. 25B6; adjective
they found him senseless on the floor : UNCONSCIOUS, stunned, insensible, insensate, comatose, knocked out, out cold, out for the count; numb; informal KO'd, dead to the world; Brit. informal spark out.
a senseless waste : POINTLESS, futile, useless, needless, unavailing, in vain, purposeless, meaningless, unprofitable; absurd, foolish, insane, stupid, idiotic, ridiculous, ludicrous, mindless, illogical.
conscious, wise.