The Collaborative International Dictionary
Undershut
Undershut \Un"der*shut`\, a. Closed from beneath.
Undershut valve (Mach.), a valve which shuts by being
lifted against a seat facing downward.
--Knight.
Wiktionary
undershut
a. close from beneath.
Usage examples of "undershut".
His waistline looked as if he had fed lavishly but not necessarily well all his life, and all the lines of his face and body were just getting filmed over and thickened and muddied with flesh, so that even his big undershut jaw looked more like elephantiasis than determination.