The Collaborative International Dictionary of English v.0.48:
Runty \Runt"y\, a. Like a runt; diminutive; mean. [1913 Webster]WordNet (r) 3.0 (2006):
runty adj 1: well below average height [syn: pint-size, pint- sized, runty, sawed-off, sawn-off] 2: (used especially of persons) of inferior size [syn: puny, runty, shrimpy]