Dip also has several vernacular meanings. It's often used a synonym for smokeless tobacco, specifically the kind of loose-cut and moistened snuff that one takes by packing into the space between the lower lip and the gums. This presumably comes from the usage of the verb dip for the taking of that tobacco, which is old enough that even dear old webbie notes it.
In some dialects of the American mid-Atlantic seaboard, dip is also an intransitive verb which, depending on context, means either or both of "to depart" or "to move quickly". When used in the second sense, it usually carries overtones of being pursued. I've got no idea of the etymology of this use, though I suspect it may have its immediate origins in AAVE.