calyx

noun (plural calyces /ˈkāləˌsēz, ˈkal-/ or calyxes)

• 1 Botany the sepals of a flower, typically forming a whorl that encloses the petals and forms a protective layer around a flower in bud. Compare with corolla.

• 2 Zoology a cuplike cavity or structure, in particular.
• a portion of the pelvis of a mammalian kidney.
• the cavity in a calcareous coral skeleton that surrounds the polyp.
• the plated body of a crinoid, excluding the stalk and arms.