necker Share definition Flag the art of slapping someone on the knape of their neck with the back of your hand. if done properly, it will sting and piss that person off. Holy shit he just gave Brandon Wiggan a necker! necker by Bobby Hoag September 23, 2008 Words you can keep railfan mug chonk mug chud mug based mug 67 mug slime mug mogging mug chopped mug thot mug glazing mug huzz mug yams mug larp mug unc mug cracked mug simp mug baddie mug bop mug lolcow mug