Simple past tense and past participle of underprop.(verb)
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Use "underpropped" in a sentence
"Finally his foot caught in the root of a tree; he tottered and would have fallen, if at that moment a dark figure had not appeared before him, and another fork "underpropped" the beast; and in the meanwhile, a voice shouted near his ear:"
"Trees newly planted must be supported, underpropped, strengthened and defended against all tempests, mischiefs, injuries, and calamities."
"What was it that founded, underpropped, and fixed, and now maintains, nourishes, and feeds the devout monks and friars in convents, monasteries, and abbeys; so that did they not daily and mightily pray without ceasing, the world would be in evident danger of returning to its primitive chaos?"