Definition of: chin

(chin) noun
1. Anat. The central and anterior part of the lower jaw. ◆ Collateral adjectives: genial ², mental.
2. Entomol. The second sclerite of the labium of an insect.
3. Zool. A small ciliated muscular process below the mouth, as in certain rotifers (genus Pedalion).
—v. chinned, chin·ning v.t. To lift (oneself) by the hands until the chin is level with the hands.
—v.i. U.S. Colloq. To talk idly. [OE cin]