snag

noun

1. a tree or part of a tree held fast in the bottom of a river, lake, etc., and forming an impediment or danger to navigation.
2. a short, projecting stump, as of a branch broken or cut off.
3. any sharp or rough projection.
4. a jagged hole, tear, pull, or run in a fabric, as caused by catching on a sharp projection.
5. any obstacle or impediment.
6. a stump of a tooth or a projecting tooth; snaggletooth.