Definition of concave in US English:



  • Having an outline or surface that curves inward like the interior of a circle or sphere.

    Compare with convex (sense 1)
    • ‘The exterior walls were composed of concave and convex red bricks.’
    • ‘You maintain your lower back curve, which is concave, by sitting straight in your chair.’
    • ‘The first surface of the head support arm is concave and the second surface of the head support arm is convex.’
    • ‘Galileo's telescope had a convex object lens but a concave eye-piece.’
    • ‘The shape of each is similar, with a slightly concave surface, a rolled rim, and a high foot ring.’
    • ‘Above it, to signal the presence of occupied space, is a shallow concave circle dug out of the ground.’
    • ‘Choose only firm tubers and look for those with tiny sprouts showing on their upper, concave surfaces.’
    • ‘The human shoulder blade is a thin triangle of bone with a thick crest along one edge, and a shallow, concave joint surface in one corner.’
    • ‘As the enamel shrinks on melting and cools with a concave surface, more has to be poured in and the process repeated.’
    • ‘It is possible to see the outline of a concave façade and shallow forecourt.’
    • ‘Depressions are concave regions on protein surfaces that have no constriction at the mouth.’
    • ‘Its profile may show anything from a rather gentle concave upward curve to a series of complex scarps and sediment-filled basins.’
    • ‘You stand in a dark room looking at a round concave surface perhaps five feet in diameter.’
    • ‘If the outside edges appear to get sanded first, yet the middle part isn't affected, then you have a concave surface.’
    • ‘This is a small group of specialized ellesmerocerids with a concave outline of siphuncle segments.’
    • ‘Similar double curvatures were used for concave lenses, and even more complicated corrections for astigmatism.’
    • ‘The articular surface itself is concave, not convex as in many chelonioids.’
    • ‘McElwee contrasts convex and concave forms with building recesses and relief carvings.’
    • ‘Where the old car had concave surfaces on the doors, the new doors swell outwards, lending more bulk to the profile.’
    • ‘Pictures of bound feet show the toes bent right under the sole, which is so curved it is concave.’
    curved inwards, hollow, hollowed out, scooped out, depressed, sunken
    View synonyms


Late Middle English: from Latin concavus, from con- ‘together’ + cavus ‘hollow’.