1. a lot of bubbles that stick together on the surface of a liquid and usually look white
a. a thick substance containing a lot of bubbles, used for cleaning, washing, or stopping fires
2. a soft light rubber or plastic substance containing many very small holes, used especially for making furniture more comfortable
Origin and usage
The word foam comes from the Old English word ‘fam’ meaning ‘foam, saliva froth; of the sea’. It first appeared in English sometime around 1300. Use of the word foam to describe the rubber or plastic substance is more recent, dating from 1937.
Foam refers to either a substance formed from many, many bubbles that stick together or a soft man-made material used to make furniture more comfortable or to protect fragile items during shipping.
Cleaning foam is popular for household use. It usually comes in a spray bottle or can. Because foam is thicker than liquid, it sticks to surfaces longer and as the bubbles in the foam burst and pop they help lift dirt off of surfaces. Cleaning foam is mostly used in kitchens and bathrooms, and on carpet, fabrics and fabric-covered furniture.
Foam can also be used to insulate houses and other structures against dramatic changes in temperature. Foam insulation must be professionally installed using a special set of tools like hoses and powerful blowers. The foam is sprayed along the inside of walls or ceilings, helping to block gaps and prevent air from escaping through tiny cracks. This helps keep homes cooler in warm weather and warmer in cold weather.
A different kind of man-made foam is used to pad furniture. This foam can be cut and formed to almost any shape, and is most often used for chairs, sofas and mattresses.