bolster (v.)youdaoicibaDictYouDict[bolster 词源字典]
mid-15c. (implied in bolstered), "propped up, made to bulge" (originally of a woman's breasts), from bolster (n.). Figurative sense is from c. 1500, on the notion of "to support with a bolster, prop up." Related: Bolstering.[bolster etymology, bolster origin, 英语词源]
shore (v.)youdaoicibaDictYouDict
mid-14c., "to prop, support with a prop;" of obscure etymology though widespread in Germanic (Middle Dutch schooren "to prop up, support," Old Norse skorða (n.) "a piece of timber set up as a support"). Related: Shored; shoring. Also as a noun, "post or beam for temporary support of something" (mid-15c.), especially an oblique timber to brace the side of a building or excavation.