concavity
From Longman Dictionary of Contemporary EnglishRelated topics: Technologyconcavitycon‧cav‧i‧ty /kənˈkævəti/ noun (plural concavities) formal 1 [uncountable]TBEND the state of being concave2 [countable]TBEND a place or shape that is curved inwardsExamples from the Corpusconcavity• With one fierce and skilful kick of his aching foot he will mend a deep concavity in the refrigerator's flank.