underlay

/ˌʌndərˈleɪ/
verb
  1. To place something under another thing for support, cushioning, or protection.
    • She decided to underlay the rug with a non-slip mat to prevent accidents.
    • We need to underlay the carpet with a thick foam pad to make it softer.
    • The roofer will underlay the shingles with a waterproof membrane.
Antonyms
noun
  1. A layer of material placed under a surface covering (such as carpet, flooring, or roofing) for cushioning, insulation, or protection.
    • Make sure the underlay is smooth before laying the laminate flooring.
    • The new carpet comes with a built-in underlay that reduces noise.
    • A good underlay can extend the life of your roof by preventing moisture damage.
What does "underlay" mean? | whatsthatwordmean | whatsthatwordmean