Home›Browse›I›intrathecalintrathecalOur editors are putting together more complete content — check back in about 20 minutesintrathecalintrathecal — adjectiveadjective1. relating to or introduced into the space under the membranes around the spinal c1.adjectiveDefinitionrelating to or introduced into the space under the membranes around the spinal cordExampleThe medication was administered via intrathecal injection.