One who's face goes from lip straight to neck, completely skipping the desirable chin. These people are heartless soulstealers who inhabit the dumps of society... Only with the addition of a chin could a lip-necker ever become a true member of the upper crust.
Tyler: "Jeff! Look out! There's a lip-necker to your immediate left!"
Jeff: "Whew! Thanks for the warning man, that was a close one."
Jeff: "I want u to meet my friend Barbara"
Tyler: " WTF man, that bitch was a total lip-necker! I almost lost my reputation and my lunch!"