mattress n.

c. 1300, materas, "a bed consisting of a bag filled with soft and elastic material and usually tacked at short intervals to prevent the contents from slipping," from Old French materas (12c., Modern French matelas), from Italian materasso and directly from Medieval Latin matracium, borrowed in Sicily from medieval Arabic al-matrah "(the) large cushion or rug for lying on" (also source of Spanish almadraque "mattress," Provençal and Catalan-Latin almatrac), literally "the thing thrown down," from taraha "he threw (down)" with noun prefix ma-. In Middle English also materace, matrasse, etc.,; the modern spelling is attested by early 15c.