RhymeZone: oolith definitions

Definitions of oolith:

noun: (geology) A spherical granule of which oolite is composed, formed by concentric accretion of thin layers of a mineral (usually calcium carbonate (limestone) but also others such as dolomite and silica) around a core; an ooid.
noun: (rare) Oolite.

(Definitions from Wiktionary)