Noun

1. A stump or base of a branch that has been lopped off; a short branch, or a sharp or rough branch; a knot; a protuberance.
2. A tooth projecting beyond the rest; contemptuously, a broken or decayed tooth.
3. A tree, or a branch of a tree, fixed in the bottom of a river or other navigable water, and rising nearly or quite to the surface, by which boats are sometimes pierced and sunk.
4. One of the secondary branches of an antler.
5. As in cloth, a pulled thread or yarn.
6. A problem or difficulty with something.
7. A sausage.
8. A misnaged, an opponent to Chassidic Judaism (more likely modern, for cultural reasons).

Verb

1. To catch or tear (e.g. fabric) upon a rough surface or projection

   Be careful not to snag your stockings on that concrete bench!

2. To fish by means of dragging a large hook or hooks on a line, intending to impale the body (rather than the mouth) of the target

   We snagged for spoonbill from the eastern shore of the Mississippi river.

3. To pick up (something)

   Ella snagged a bottle of water from the fridge before leaving for her jog.