Webster's Revised Unabridged Dictionary · 1913

Borer

Borer ({not transcribed}) , noun

1.
One that bores; an instrument for boring.
2.
(a) (Zoology) A marine, bivalve mollusk, of the genus Teredo and allies, which burrows in wood. See Teredo.
(b)
(Zoology) Any bivalve mollusk (Saxicava, Lithodomus, etc.) which bores into limestone and similar substances.
(c)
(Zoology) One of the larva of many species of insects, which penetrate trees, as the apple, peach, pine, etc. See Apple borer, under Apple.
(d)
(Zoology) The hagfish (Myxine).