multilocular

Multilocular is an adjective used in biology to describe something that is divided into, or composed of, many compartments or locules. The word derives from Latin multi- 'many' and loculus 'a small place or compartment'. The term is applied across disciplines to indicate multipartition, rather than shape alone.

In anatomy and histology, multilocular describes tissues in which multiple small spaces are present. Brown adipose tissue features multilocular adipocytes containing many small lipid droplets, in contrast to white adipose tissue, where adipocytes are typically unilocular with a single large lipid droplet. In pathology and medical imaging, cystic or tumorous lesions may be described as multilocular when their lumen is partitioned by septa into several chambers, such as multilocular cystadenomas or multilocular cystic neoplasms. The distinction between uni- and multilocular morphology can influence differential diagnosis and management.

In botany, multilocular is used for structures with several compartments. For example, many flowering plants have multilocular anthers with multiple pollen sacs, and some fruits or ovaries are divided into several locules.

In other contexts, the term also appears in radiology, paleontology, and embryology to describe any organ, tissue, or structure exhibiting multiple chambers or compartments. The related term multiloculated is often used synonymously with multilocular, particularly in imaging and histology reports.