concavity.

1. An inward-curving form, depression or hollow, or the condition of having such a form.

2. The condition in which a function’s graph lies on or above the line segment joining any two points in its domain.

Use it for

Words that belong together

• concavity of a surface
• shallow concavity

On the page

A shallow concavity collected rain near the center of the stone.

The concavity of the surface became clear when the straight edge rested across it.

Usage notes

Primary category: setting / description. Forms: Singular concavity; plural concavities. Also uncountable. Legacy lexical fields mirror sense 1 only. Use numbered sense fields for all meanings. Established modern English lexical item. No separate regional spelling or grammatical inflection entry. Writing functions: spatial orientation, setting description, material description, contrast. Disciplines: descriptive writing, physical setting, spatial analysis. Commonness: uncommon.