concave

US /ˈkɑːn.keɪv/
UK /ˈkɑːn.keɪv/
"concave" picture
1.

cóncavo

having an outline or surface that curves inward like the interior of a circle or sphere

:
The spoon has a concave shape.
La cuchara tiene una forma cóncava.
The lens of the telescope is concave.
La lente del telescopio es cóncava.