a large thick pad filled with resilient material and often incorporating coiled springs, used as a bed or part of a bed
"She bought a new mattress to replace the old sagging one in her bedroom."
A pad on which a person can recline and sleep, usually having an inner section of coiled springs covered with foam or other cushioning material then enclosed with cloth fabric.
"After the long journey, she finally collapsed onto her new mattress to get some much-needed rest."
In plain English: A mattress is the thick, cushioned pad you sleep on inside your bed to make it comfortable.
"She bought a new mattress to replace the old one in her bedroom."
Usage: A mattress is the padded surface used for sleeping that typically contains coils and foam layers. While you can use it as a verb meaning to cover something completely, this usage is rare in everyday conversation compared to its primary role as a noun referring to bed furniture.
To cover with a thick layer, like a mattress; to blanket.
"The heavy snowfall eventually blanketed the entire valley in a deep drift of white powder."
In plain English: To mattress something means to cover it with soft padding so that it feels comfortable and safe.
"The mattress sank under his weight when he lay down on the bed."
The word "mattress" comes from Arabic maṭraḥ, meaning a place where something is thrown. It entered English through Old French and Middle English after describing soft bedding used by people in the Middle East who were accustomed to lying on padded floors rather than hard surfaces.