Falx

Falx is a Latin word meaning sickle. In English usage it denotes anything curved or sickle-shaped, and in specialized fields it names particular structures or weapons. The term is applied across disciplines to describe shape, often as a descriptive label rather than a specific brand or type.

Falx cerebri is a crescent-shaped fold of dura mater that descends into the longitudinal fissure between the brain’s two cerebral hemispheres. It attaches anteriorly to the crista galli of the ethmoid bone and posteriorly to the internal occipital crest, helping to partition the hemispheres and house the superior sagittal sinus. Falx cerebelli is a smaller dural fold that separates the two cerebellar hemispheres, running along the midline in the posterior cranial fossa and attaching to the internal occipital crest and tentorium cerebelli.

The falx also refers to a historical weapon. The Dacian falx was a long, curved, single-edged blade used by ancient peoples in the region of what is now Romania and surrounding areas. Descriptions from classical sources portray it as a heavy, sickle-like weapon capable of powerful slashes, sometimes argued to undermine shields. Archaeological and literary evidence has led to some debate about its precise design and regional variants, but it remains a well-known example of a curved cutting blade in ancient warfare.

In other contexts, falx is used more broadly to name any anatomical or structural feature that is sickle-shaped, emphasizing curvature over size.