chin (n.) Look up chin at Dictionary.com
Old English cin, cinn "chin" (but in some compounds suggesting an older, broader sense of "jawbone"); a general Germanic word (compare Old Saxon and Old High German kinni; Old Norse kinn; German Kinn "chin;" Gothic kinnus "cheek"), from PIE root *genu- "chin, jawbone" (cognates: Sanskrit hanuh, Avestan zanu- "chin;" Armenian cnawt "jawbone, cheek;" Lithuanian žándas "jawbone;" Greek genus "lower jaw," geneion "chin;" Old Irish gin "mouth," Welsh gen "jawbone, chin").
chin (v.) Look up chin at Dictionary.com
1590s, "to press (affectionately) chin to chin," from chin (n.). Meaning "to bring to the chin" (of a fiddle) is from 1869. Slang meaning "talk, gossip" is from 1883, American English. Related: Chinned; chinning. Athletic sense of "raise one's chin over" (a raised bar, for exercise) is from 1880s.