lacune

Lacune is a noun borrowed from Latin lacuna, meaning "gap" or "hollow." In English it denotes a small cavity, space, or interval within a material or structure, or a missing portion in a text or body of knowledge. The plural is lacunae.

In anatomy and histology, lacunae are tiny cavities that house cells. Bone lacunae contain osteocytes; cartilage lacunae contain chondrocytes. Lacunae can also describe other small spaces within tissues and are typically surrounded by extracellular matrix.

In medicine, lacunae appear in neuropathology as lacunar infarcts—small, deep brain strokes due to occlusion of penetrating arteries. Clinically, these infarcts can cause pure motor or sensory deficits, depending on the affected territory. The term may also be used descriptively for microscopic cavities in pathological tissue.

In the humanities, lacuna denotes a gap or missing portion in a manuscript, inscription, or body of knowledge. It is used to indicate incomplete transmission, damage, or the absence of evidence for a given period or topic.