falc-

Sickle-shaped.

Latin falx, falc‑, sickle.

Something falciform or falcate is hooked or curved like a sickle; a falx (plural falces) is a sickle-shaped fold in the membrane enveloping the brain and spinal cord; falciparum is the most severe form of malaria, caused by infection with Plasmodium falciparum.