"a split, crack," 1530s, with unetymological -k + Middle English chine (and replacing this word) "fissure, narrow valley," from Old English cinu, cine "fissure," which is related to cinan "to crack, split, gape," a common Germanic word (compare Old Saxon and Old High German kinan, Gothic uskeinan, German keimen "to germinate;" Middle Dutch kene, Old Saxon kin, German Keim "germ"). The connection being in the notion of bursting open.
"sharp, clear, metallic sound" (especially of coin), 1580s, probably imitative. As a verb from 1580s. Related: Chinked; chinking.