noun the hagfish (myxine).
2. borer ·noun one that bores; an instrument for boring.
3. borer ·noun any bivalve mollusk (saxicava, lithodomus, ·etc.) which bores into limestone and similar substances.
4. borer ·noun a marine, bivalve mollusk, of the genus teredo and allies, which burrows in wood. ·see teredo.
5. borer ·noun one of the larvae of many species of insects, which penetrate trees, as the apple, peach, pine, ·etc. ·see apple borer, under apple.