Question

select the part of speech in this dictionary entry.
cascade kas-kayd noun pl cascades 1. a small, steep waterfall: the boys threw rocks into the cascade. 2. something that flows forth, resembling a waterfall: the skirt was composed of layers of cloth arranged in a cascade. 3. a large number of events that happen quickly in a series: hayley was plagued by a cascade of thoughts that kept her awake. — from italian (cascare)

Explanation:

The dictionary entry explicitly labels "cascade" as a noun immediately after its pronunciation, and the example sentences use it as a noun (referring to a thing/concept).

Answer:

Noun