un·der·neath / ˌəndərˈnē[unvoicedth]/ • prep. & adv. 1. situated directly below (something else): [as prep.] our bedroom is right underneath theirs | [as adv.] his eyes were red-rimmed with black bags underneath | [as adj.] on longer hair, the underneath layers can be permed to give extra body. ∎ situated on a page directly below (a picture or another piece of writing): [as prep.] four names written neatly underneath one another | [as adv.] there was writing underneath. 2. so as to be concealed by (something else): [as prep.] money changed hands underneath the table | fig. underneath his aloof air, Nicky was a warm and open young man | [as adv.] paint peeling off in flakes to reveal grayish plaster underneath. ∎ partly or wholly concealed by (a garment): [as prep.] she could easily see the broadness of his shoulders underneath a tailored white shirt | [as adv.] I wear button-downs, and my T-shirts show underneath. • n. [in sing.] the part or side of something facing toward the ground; the underside.