hockyoudaoicibaDictYouDict[hock 词源字典]
hock: English has three words hock. The oldest, ‘joint of a quadruped corresponding to the human ankle’ [16], is short for an earlier hockshin, which comes from Old English hōhsinu. This meant literally ‘heel-sinew’, and the hōh came from the same prehistoric Germanic source as produced modern English heel. In its original sense it can also be spelled hough, but for ‘joint of bacon’, first recorded in the 18th century, hock is the only spelling. Hock ‘Rhinewine’ [17] is short for an earlier hockamore, an anglicization of Hochheimer (Hochheim, on the river Main, is a centre of German wine production). Hock ‘pawn, debt’ [19] comes from Dutch hok ‘prison’, hence ‘debt’; it was introduced to English by Dutch immigrants in the USA.

The -hock of hollyhock, incidentally, comes from Old English hoc ‘mallow’ (and the holly- is an alteration of holy, and has no connection with holly).
=> heel[hock etymology, hock origin, 英语词源]
hock (n.1)youdaoicibaDictYouDict
"joint in the hind leg of a horse," mid-15c., earlier hockshin (late 14c.), from Old English hohsinu "sinew of the heel, Achilles' tendon," literally "heel sinew," from hoh "heel," from Proto-Germanic *hanhaz (cognates: German Hachse "hock," Old English hæla "heel"), from PIE *kenk- (3) "heel, bend of the knee."
hock (n.2)youdaoicibaDictYouDict
"Rhenish wine," 1620s, shortening of Hockamore, from German Hochheimer, "(wine) of Hochheim," town on the Main where wine was made; sense extended to German white wines in general.
hock (n.3)youdaoicibaDictYouDict
"pawn, debt," 1859, American English, in hock, which meant both "in debt" and "in prison," from Dutch hok "jail, pen, doghouse, hutch, hovel." The verb is 1878, from the noun.
When one gambler is caught by another, smarter than himself, and is beat, then he is in hock. Men are only caught, or put in hock, on the race-tracks, or on the steamboats down South. ... Among thieves a man is in hock when he is in prison. [G.W. Matsell, "Vocabulum," 1859]