Source : Webster's Revised Unabridged Dictionary (1913)

Runty \Runt"y\, a.
   Like a runt; diminutive; mean.

Source : WordNet®

runty
     adj 1: well below average height [syn: {pint-size}, {pint-sized}, {sawed-off},
             {sawn-off}]
     2: (used especially of persons) of inferior size [syn: {puny},
        {shrimpy}]