pneumogastric vs vagal

pneumogastric is a noun but vagal is not a noun.

Word	Noun	Adjective	Verb	Adverb
pneumogastric	Yes	Yes	No	No
vagal	No	Yes	No	No

As adjectives, pneumogastric and vagal are synonyms defined as:

pneumogastric (noun)	vagal (noun)
a mixed nerve that supplies the pharynx and larynx and lungs and heart and esophagus and stomach and most of the abdominal viscera

pneumogastric (adjective)	vagal (adjective)
of or relating to or involving the lungs and stomach	of or relating to the vagus nerve
of or relating to the vagus nerve