Source : Webster's Revised Unabridged Dictionary (1913)

Toothless \Tooth"less\, a.
   Having no teeth. --Cowper.

Source : WordNet®

toothless
     adj 1: lacking teeth; "most birds are toothless"; "a toothless old
            crone" [ant: {toothed}]
     2: lacking necessary force for effectiveness; "a toothless
        piece of legislation"