BATTEN, (1) A term (a form of "baton") used in joinery (q.v.) for a board not more than 4 to 7 in. broad or 3 in. thick, used for various purposes, such as for strengthening or holding together laths and other wood-work; and specially, on board ship, a strip of wood nailed to a mast to prevent rubbing, or fixing down a tarpaulin over a hatchway, in rough weather, to keep out water. (2) A verb (the root is found in words of several Teutonic languages meaning profit or improvement, and also in the English "better" and "boot") meaning to improve in condition, especially in the case of animals by feeding; so, to feed gluttonously; the word is used figuratively of prospering at the expense of another.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)