"pertaining to the vagus," 1846, from vagus + -al (1).
Entries linking to vagal
vagus n.
plural vagi, 1840, "pneumogastric nerve," the long, widely distributed nerve from the brain to the upper body, from Latin vagus "wandering, straying" (see vague).
-al 1
suffix forming adjectives from nouns or other adjectives, "of, like, related to, pertaining to," Middle English -al, -el, from French or directly from Latin -alis (see -al (2)).