Source : Webster's Revised Unabridged Dictionary (1913)

Forceless \Force"less\, a.
   Having little or no force; feeble.

         These forceless flowers like sturdy trees support me.
                                                  --Shak.

Source : WordNet®

forceless
     adj : lacking force; feeble; "a forceless argument" [syn: {unforceful},
            {weak}] [ant: {forceful}]