Describes a surface or shape that is depressed inward, like a dent or a concave curve. Often used for physical objects or terrain.
This plate is hollowed out in the middle.
Concave terrain tends to collect rainwater.
Compound of 中 (なか, 'center') and 低 (ひく, 'low'), literally meaning 'center-low'. The reading なかびく is a combination of the kun'yomi of both characters.