underslung vs underhung

underslung and underhung both are adjectives.

Word	Noun	Adjective	Verb	Adverb
underslung	No	Yes	No	No
underhung	No	Yes	No	No

As adjectives, underslung and underhung are synonyms defined as:

underslung and underhung: having a lower part projecting beyond the upper

Other synonyms of underslung include undershot.

underslung (adjective)	underhung (adjective)
having a low center of gravity; built low to the ground	having a lower part projecting beyond the upper
having a lower part projecting beyond the upper	supported from below especially resting on a track instead of suspended from above
supported from above especially in a vehicle having springs attached to the axle from below