to be from the notion of individual sheets of paper "fastened" into a book. Ayto offers an alternative theory: vines fastened by stakes and formed into a trellis, which led to sense of "columns of writing on a scroll." When books replaced scrolls, the word continued to be used. Page-turner "book that one can't put down" is from 1974.
"youth, lad, boy of the lower orders," c.1300, originally also "youth preparing to be a knight," from O.Fr. page, possibly via It. paggio, from M.L. pagius "servant," perhaps ult. from Gk. paidion "boy, lad," dim. of pais (gen. paidos) "child;" but some sources consider this unlikely and suggest instead
L. pagus "countryside," in sense of "boy from the rural regions" (see pagan
). Meaning "youth employed as a personal attendant to a person of rank" is first recorded c.1460; this was transf. from late 18c. to boys who did personal errands in hotels, clubs, etc., also in U.S. legislatures. The verb (1904) is from the notion of "to send a page after" someone. Pager "device that emits a signal when activated by a telephone call" is first attested 1968.