The
chunk of one's
body which holds one's
head up. Contains the
throat,
esophagus,
larynx,
carotid arteries,
jugular veins, some
lymph nodes, and a few
vertebrae, among other
organs.
As a verb, "to neck" means to engage in sexual contact of a mild sort, such as kissing and petting. This expression may come from the behavior of amorous giraffes.