Dip is a form of smokeless tobbacco, which is finer cut than chew, and is chemicially cured. Used by putting a "pinch" of the stuff between your bottom lip and gum, or less commonly the upper lip.
YOU DO NOT CHEW ON DIP! The result would be a disgusting mess, and would most likely cause you to swallow some. Swallowing dip will make make you feel very sick, and you will more than likely puke.
Used commonly among males in the Southeast US. About 75% of the males in my area use dip, including me.
Non-dipper: That shit is disgusting!
Me: It's just ground up plants you fucktard. Here, try some.
*puts a fat dip in*
This stuff is great!
Non-dipper then procedes to vomit, as I look on and laugh.