Emily Dickinson Lexicon

LUFF, v.i. [D. loeven; Arm. loffi.]

To turn the head of a ship toward the wind; to sail nearer to the wind. Hence, in the imperative, luff, is an order to put the tiller on the lee side, in order to make the ship sail nearer the wind. Luff round, or luff a-lee, is the extreme of this movement, intended to throw the ship's head into the a wind. A ship is said to spring her luff, she yields to the helm by sailing nearer the wind. – Encyc.