FOLD (3)

Fold, n. [[From Fold, v. In sense 2 AS. -feald, akin to fealdan to fold.]] 1. 1. A doubling,esp. of any flexible substance; a part laid over on another part; a plait; a plication.
Mummies . . . shrouded in a number of folds of linen. Bacon. Folds are most common in the rocks of mountainous regions. J. D. Dana. 2. 2. Times or repetitions; — used with numerals, chiefly in composition, to denote multiplication or increase in a geometrical ratio, the doubling, tripling, etc., of anything; as, fourfold, four times, increased in a quadruple ratio, multiplied by four.
3. 3. That which is folded together, or which infolds or envelops; embrace.
Shall from your neck unloose his amorous fold. Shak. Fold net, a kind of net used in catching birds.