n. [ OF. materas, F. matelas, LL. matratium; cf. Sp. & Pg. almadraque, Pr. almatrac; all from Ar. ma&tsdot_;rah a place where anything is thrown, what is thrown under something, fr. &tsdot_;araha to throw. ] [ 1913 Webster ]

1. A large pad stuffed with hair, moss, or other suitable soft material, and quilted or otherwise fastened, used as or in a bed, to support the human body while lying down. [ Written also matress. ] [ 1913 Webster ]

2. (Hydraulic Engin.) A mass of interwoven brush, poles, etc., to protect a bank from being worn away by currents or waves. [ 1913 Webster ]

innerspring mattress A variety of mattress{ 1 } having springs inside to provide a flexible support; it is considered more comfortable than a stuffed mattress. [ PJC ]