英语词源字典 - 在线词源网站

ampersand (n.)[ampersand 词源字典]: 1837, contraction of and per se and, meaning "(the character) '&' by itself is 'and' " (a hybrid phrase, partly in Latin, partly in English). The symbol is based on the Latin word et "and," and comes from an old Roman system of shorthand signs (ligatures), attested in Pompeiian graffiti, but not (as sometimes stated) from the Tironian Notes, which was a different form of shorthand, probably invented by Cicero's companion Marcus Tullius Tiro, which used a different symbol, something like a reversed capital gamma, to indicate et.

This Tironian symbol was maintained by some medieval scribes, including Anglo-Saxon chroniclers, who sprinkled their works with a symbol like a numeral 7 to indicate the word and. In old schoolbooks the ampersand was printed at the end of the alphabet and thus by 1880s had acquired a slang sense of "posterior, rear end, hindquarters."[ampersand etymology, ampersand origin, 英语词源]
bootstrap (n.): also boot-strap, tab or loop at the back of the top of a men's boot, which the wearer hooked a finger through to pull the boots on, 1870, from boot (n.) + strap (n.).

Circa 1900, to pull (oneself) up by (one's) bootstraps was used figuratively of an impossible task (Among the "practical questions" at the end of chapter one of Steele's "Popular Physics" schoolbook (1888) is, "30. Why can not a man lift himself by pulling up on his boot-straps?"). By 1916 its meaning expanded to include "better oneself by rigorous, unaided effort." The meaning "fixed sequence of instructions to load the operating system of a computer" (1953) is from the notion of the first-loaded program pulling itself, and the rest, up by the bootstrap.
school-book (n.): also schoolbook, 1745, from school (n.1) + book (n.).