ETYM Old Fren. materas, French matelas, Late Lat. matratium; cf. Spanish and Portu. almadraque, Pr. almatrac; all from Arabic matrah a place where anything is thrown, what is thrown under something, from taraha to throw.
(Irregular plural: mattresses).
1. A thick, cushioned pad placed upon a bedframe, used for sleeping.
2. A mass of interwoven brush, poles, etc., to protect a bank from being worn away by currents or waves.
A large thick pad filled with resilient material and often incorporating coiled springs, used as a bed or part of a bed.