paperback n.

mid-14c., "material consisting of a compacted web or felting of vegetable fibers, commonly as a thin, flexible sheet for writing, printing, etc.," from Anglo-French paper, Old French papier "paper, document," and directly from Latin papyrus "paper, paper made of papyrus stalks," from Greek papyros "any plant of the paper plant genus," a loan-word of unknown origin, often said to be Egyptian (see papyrus).

Sense of "essay, dissertation on a topic" is from 1660s. Meaning "bills of exchange, paper money" is attested by 1722. As "paper for covering the walls of interiors," 1764. As "printed sheet of news" (a shortened form of newspaper), attested by 1640s. Papers, "collection of documents which establish one's identity, standing, credentials, etc.," it is attested from 1680s.

Paper-clip is by 1875; paper-cutter as a type of machine is by 1969. Paper-hanger is by 1796. Paper-wasp " type of wasp that builds a nest out of paper-like material" is by 1805. Paper chase is by 1856 in British English for the game of hare-and-hounds, from the bits of paper scattered as "scent" by the "hares;" the slang meaning "effort to earn a diploma or college degree" is by 1932.

Old English bæc "back," from Proto-Germanic *bakam (cognates: Old Saxon and Middle Dutch bak, Old Frisian bek), with no known connections outside Germanic. In other modern Germanic languages the cognates mostly have been ousted in this sense by words akin to Modern English ridge (such as Danish ryg, German Rücken).

Many Indo-European languages show signs of once having distinguished the horizontal back of an animal (or a mountain range) from the upright back of a human. In other cases, a modern word for "back" may come from a word related to "spine" (Italian schiena, Russian spina) or "shoulder, shoulder blade" (Spanish espalda, Polish plecy).

By synecdoche, "the whole body," especially with reference to clothing. The meaning "upright part of a chair" is from 1520s. As a U.S. football position by 1876, so called from being behind the line of rushers; further distinguished according to relative position as quarterback, halfback, fullback. To turn (one's) back on (someone or something) "ignore" is from early 14c.

To know (something) like the back of one's hand, implying familiarity, is first attested 1893 in a dismissive speech made to a character in Robert Louis Stevenson's "Catriona":

If I durst speak to herself, you may be certain I would never dream of trusting it to you; because I know you like the back of my hand, and all your blustering talk is that much wind to me.

The story, a sequel to "Kidnapped," has a Scottish setting and context, and the back of my hand to you was noted in the late 19th century as a Scottish expression meaning "I will have nothing to do with you" [see Longmuir's edition of Jamieson's Scottish dictionary]. In English generally, the back of (one's) hand has been used to imply contempt and rejection at least since 1300. Perhaps the connection of a menacing dismissal is what made Stevenson choose that particular anatomical reference.