Home › Words › U › undercrustundercrustundercrust means A crust that forms the bottom of a pie, tart or other dish; a layer of pastry that supports the filling.Among words judged in Lexicurio's Arena, undercrust ranks #25,519 of 42,747 for Qualifying.EtymologyUnder- + crustnounA crust that forms the bottom of a pie, tart or other dish; a layer of pastry that supports the filling.e.g.“In the middle ages, our forefathers found themselves deficient in plates and so, for a substitute, an undercrust of bread served as a plate.” — 1919 September, “How Some of Our Popular Dishes Got their Names”, in Gas Logic, volume 26, number 3, page 13:The layer of material located beneath the crust of a planet or moon.e.g.“It must therefore form the undercrust of all Gallia.” — 1878, Jules Verne, To the Sun?: A Journey Through Planetary Space, page 327:Definitions & examples from Wiktionary (CC BY-SA 3.0).