foam rubber noun
[noncount] : a soft and light rubber material that has many small holes throughout it and is used to make various products
▪ The mattress/pad is (made of) foam rubber. — often used before another noun ▪ a foam-rubber mattress/pad
▪ The mattress/pad is (made of) foam rubber. — often used before another noun ▪ a foam-rubber mattress/pad
