Underneath/ˌʌndərˈniːθ/ Definition 1 of 3Pro Tip 1/3Hidden Visibility Used when something is not immediately visible because it’s covered by something else. The wiring runs underneath the floorboards. Pro Tip 2/3Figurative Use Can describe deeper layers of meaning or feelings not immediately visible. Underneath his tough exterior, he's very sensitive. Pro Tip 3/3Physical Contact Implies direct contact with the underside of the object above. She slipped the gift underneath the Christmas tree.