snag

n. [ Prov. E., n., a lump on a tree where a branch has been cut off; v., to cut off the twigs and small branches from a tree, of Celtic origin; cf. Gael. snaigh, snaidh, to cut down, to prune, to sharpen, p. p. snaighte, snaidhte, cut off, lopped, Ir. snaigh a hewing, cutting. ] 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. [ 1913 Webster ]

The coat of arms
Now on a naked snag in triumph borne. Dryden. [ 1913 Webster ]

2. A tooth projecting beyond the rest; contemptuously, a broken or decayed tooth. Prior. [ 1913 Webster ]

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. [ 1913 Webster ]

4. (Zool.) One of the secondary branches of an antler. [ 1913 Webster ]

[ 1913 Webster ]

Snag boat, a steamboat fitted with apparatus for removing snags and other obstructions in navigable streams. [ U.S. ] --
Snag tooth. Same as Snag, 2. [ 1913 Webster ]

How thy snag teeth stand orderly,
Like stakes which strut by the water side. J. Cotgrave. [ 1913 Webster ]