noun, plural -ties. a downward slope, as of ground (opposed to acclivity).
de·cliv·i·ty (d-kl v-t) n. pl. de·cliv·i·ties. A downward slope, as of a hill. [Latin d cl vit s, from d cl vis, sloping down: d-, de-+ cl vus, slope; see klei-in Indo ...
declivity: Definition and Pronunciation