hollow

curved inward there's a noticeably hollow spot in the mattress where he has been sleeping Synonyms concave, dented, depressed, dished, indented, recessed, sunken Related Words alveolar, cavernous, crescentic, cuplike, cupped, cuppy, recurved; dimpled, pockmarked; compressed, condensed, contracted, diminished, reduced Near Antonyms ballooning, bloated, blown up, bulbous, distended, enlarged, expanded, extended, inflated, jutting, projecting, puffed, puffy, risen, swollen; domed, global, globular, round, rounded, spherical Antonyms bulging, cambered, convex, protruding, protrusive, protuberant

1 a sunken area forming a separate space made a little hollow in her mound of mashed potatoes and filled it with gravy Synonyms cavity, concavity, dent, depression, dint, hole, indentation, indenture, pit, recessRelated Words burrow, cave, cavern, ditch, excavation, furrow, groove, gutter, trench, trough; basin, bowl, valley; alcove, cleft, niche, nook, opening, recess, socket; alveolus, dimple, gouge, impression, imprint, notch, pocket; borehole, chuckhole, crater, posthole, pothole, sinkhole, wallow, water hole, well; abyss, chasm, gulf, vacuity, vacuum, voidNear Antonyms hill, mound, rise; bump, bunch, hump, lump, pimple, swell, swelling, tumorAntonyms bulge, camber, convexity, jut, projection, protrusion, protuberance

2 an area of lowland between hills or mountains a quaint village nestled in a hollow among green hills Synonyms dale, dene [British], valley, valeRelated Words canyon (also cañon), combe (also coombe or coomb) [British], dell, depression, dingle, glen, gorge, gulch, gully (also gulley), kloof [South African], ravine, rift valley; basin, bowlNear Antonyms alp, mount, mountain, peak; height, mountaintop, pinnacle, summit; plateau, tableland