calyx

Etymology

From Latin calyx, from Ancient Greek κάλυξ (kálux, “case of a bud, husk”). Doublet of chalice and kelch.

noun

1. (botany) The outermost whorl of flower parts, comprising the sepals, which covers and protects the petals as they develop.
   Meronym: sepal
2. (zoology, anatomy) Any of various cup-like structures.
   1. A chamber in the mammalian kidney through which urine passes.
   2. The crown containing the viscera of crinoids and similar echinoderms, entoprocts, and the polyps of some cnidarians.
   3. A funnel-shaped expansion of the vas deferens or oviduct of insects.
   4. A flattened cap of neuropil in the brain of insects.