concavity

What it means

1. uncountableThe state of being concave.

   The concavity of the bowl was crucial for storing water in Paleolithic times.

2. countableA concave structure or surface.

   The pumice had small concavities called vesicles inside it.

   1 more example

   On top of the rock there is a concavity, like a bowl, and that's where we meet.

   2023, Dave Eggers, illustrated by Shawn Harris, The Eyes and the Impossible, page 25

In a sentence

The concavity of the bowl was crucial for storing water in Paleolithic times.

Where it comes from

1. Old Frenchconcavité
2. Englishconcavity

From Old French concavité. Morphologically concave + -ity.