concavity

concavity
    n 1: a shape that curves or bends inward [syn: {concave shape},
         {concavity}, {incurvation}, {incurvature}]
    2: the property possessed by a concave shape [syn: {concavity},
       {concaveness}]
    

Concavity \Con*cav"i*ty\, n.; pl. {Concavities}. [L. concavitas:
   cf. F. concavit['e]. See {Concave}.]
   A concave surface, or the space bounded by it; the state of
   being concave.
   [1913 Webster]
    

118 Moby Thesaurus words for "concavity":
      aduncity, alveolation, alveolus, antrum, aquilinity, arching,
      arcuation, armpit, basin, boss, bowl, bump, cavity, circularity,
      colophon, concameration, concave, convexity, convolution, crater,
      crookedness, crypt, cup, curvation, curvature, curving, curvity,
      dactylogram, dactylograph, de-escalation, debasement, decurvation,
      decurvature, degradation, demotion, dent, depression, descent,
      detrusion, diminution, dint, dip, ducking, embossment, excrescence,
      excurvation, excurvature, fingerprint, fold, follicle, footmark,
      footprint, footstep, fossil footprint, funnel chest, hauling down,
      hole, hollow, hollow shell, hollowness, hookedness, ichnite,
      ichnolite, impress, impression, imprint, incurvation, incurvature,
      incurvity, indent, indentation, indention, lacuna, lowering, lump,
      pad, paw print, pawmark, pimple, pit, pocket, print, pug, pugmark,
      punch bowl, recurvation, recurvature, recurvity, reduction,
      rondure, rotundity, sag, scoop, seal, shell, sigil, signet, sink,
      sinkage, sinkhole, sinking, sinuosity, sinuousness, sinus, socket,
      stamp, step, stud, submergence, thrusting under, thumbmark,
      thumbprint, tortuosity, tortuousness, trough, vaulting, vestige,
      vug