Origin and history of loan

"grant temporary possession of," late 14c., from past tense of Old English lænan "to grant temporarily, lease out, make loans, lend money at interest," from Proto-Germanic *laihwnjan, verb derived from *loikw-nes-, the prehistoric source of Old English læn "gift" (see loan (n.)). Compare Dutch lenen, Old High German lehanon, German lehnen, all verbs derived from nouns. In Middle English the past tense form, with terminal -d, became the principal form on analogy of bend, send, etc. To lend an ear "listen" is from late 14c.

"large, voracious fish," by 1560s, perhaps mid-15c., if an isolated instance in a diary quoted in Middle English Compendium is the same word, of uncertain origin.

The meaning "dishonest person who preys on others," though attested from 1599 (sharker "artful swindler" in this sense is from 1594), may be the original sense, later transferred to the large, voracious marine fish. If so, it is possibly from German Schorck, a variant of Schurke "scoundrel, villain," agent noun of Middle High German schürgen (German schüren) "to poke, stir."

On an old theory, the English word is from a Mayan word, xoc, which might have meant "shark." Northern Europeans seem not to have been familiar with the larger sort of sharks before voyages to the tropics began. A slightly earlier name for it in English was tiburon, from Spanish tiburón (1520s), which probably is from a native word from South America, such as Tupi uperu "shark" (source also of Portuguese tubarão, Catalan tauró).

Middle English had hound-fish (early 14c.), which probably was used of dogfish and other small sharks. The general Germanic word seems to be represented by Old Norse har (Norwegian hai, Danis haj, Dutch haai, German Hai, also borrowed in Finnish, Latvian), which is of unknown origin. French requin is literally "grimacer," from Norman requin, from Old French reschignier "to bare the teeth, grimace."

An ancient Greek word for a shark was karkharias, from karkharos "sharp, jagged, biting," but the old theory that traces the English word to this has been dropped. Other Greek words for large selachians were aetos, bous, lamia, narkē; skylion was "dogfish." Latin used squalus, from the root of English whale (n.); Lithuanian ryklys is literally "swallower."

The English word was applied (or re-applied) to voracious or predatory persons, on the image of the fish, from 1707 (originally of pick-pockets); loan shark is attested from 1905.

There is the ordinary Brown Shark, or sea attorney, so called by sailors; a grasping, rapacious varlet, that in spite of the hard knocks received from it, often snapped viciously at our steering oar. [Herman Melville, "Mardi"]