A chamber in the mammalian kidney through which urine passes.
The outermost whorl of flower parts, comprising the sepals, which covers and protects the petals as they develop.
The crown containing the viscera of crinoids and similar echinoderms, entoprocts, and the polyps of some cnidarians.
A flattened cap of neuropil in the brain of insects.
A funnel-shaped expansion of the vas deferens or oviduct of insects.
A space visible between cells, allowing free passage of light.
Any gap, break, hole, or lack in a set of things; something missing.
A language gap, which occurs when there is no direct translation in the target language for a lexical term found in the source language.
An absent part, especially in a book or other piece of writing, often referring to an ancient manuscript or similar.
A small blank space; a gap or vacancy; a hiatus.
A small opening; a small pit or depression, especially in bone.