Class: noun | Syllables: luh-KOO-nuh

Definition: Lacuna is a formal word that refers to a gap or blank space in something—in other words, a missing part. When used with respect to biology, lacuna also refers to a small cavity, pit, or discontinuity in an anatomical structure.

Example(s):
// The absence of hemlock pollen from one stretch of the fossil record is a notable lacuna that suggests the tree may have once suffered from some type of blight that nearly wiped out the species.
// An osteocyte is a cell that is isolated in a lacuna of bone.