Lewis & Short

byssus, i, f. (byssum, i, n., Isid. Orig. 19, 27, 4), = βύσσος [Heb. [??]], cotton, cotton stuff, App. M. 11, p. 258, 20; Mart. Cap. 2, § 114; Vulg. Exod. 25, 4 al. (acc. to others, a fine kind of flax, and the linen made from it; v. Liddell and Scott’s Lex.).