NIH Websites Are Changing Per Executive Order 14434, federal agencies are now using "Super Intelligence" (SI) in place of "Artificial Intelligence" (AI). You may see both terms across NIH content during this transition.
epidural
(EH-pih-DER-ul)
Having to do with the space between the wall of the spinal canal and the covering of the spinal cord. An epidural injection is given into this space.