concavity
noun /kɒnˈkævəti/
/kɑːnˈkævəti/
(plural concavities)
(specialist)- [uncountable] the quality of being concave (= curving in)
- Rocks exposed to wind often show some degree of concavity.
- [countable] a shape or place that curves in
- a deep concavity in the side of the hill