falx

noun6

1. •
   Any sickle-shaped part or process.
2. •
   A curved fold or process of the dura mater or the peritoneum, especially one of the partition-like folds of the dura mater which extend into the great fissures of the brain.
3. •
   A snake's poison fang.
4. •
   A rotula of a sea urchin.
5. •
   (old-fashioned) A chelicera.
6. •
   (historical) A short Dacian sword resembling a sickle.