WordNet sense 1 (held up or having the weight borne especially from below):

supported

WordNet sense 2 (thrusting outward):

protrusive

WordNet sense 3 (having a lower part projecting beyond the upper):

undershot, underhung

WordNet sense 4 (having a low center of gravity; built low to the ground):

squat

WordNet sense 5 (literal meanings; being at or having a relatively small elevation or upward extension):

low