What is another word for underlay?
Pronunciation: [ˌʌndəlˈe͡ɪ] (IPA) 
Underlay is a term used in reference to a material that is placed under another material to provide additional support or protection. Synonyms for the word underlay include base, lining, padding, underpinning, groundwork, substrate, layer, and cushion. These synonyms can be used interchangeably in various contexts to describe the same concept of providing a foundation or support for another material. For example, a carpet underlay can be described as a padding or substrate, while an underlay for vinyl flooring can be called a lining or base. Regardless of the word used, the purpose of an underlay remains the same, to add strength, protection, and longevity to the surface material.
