What is vagal inhibition?

Since this is not my area of expertise, I searched Google under the key words "vagal inhibition" to get these possible sources:

http://www.bio.net/hypermail/neur-sci/1999-April/037752.html
http://www.dundee.ac.uk/forensicmedicine/notes/water.pdf

In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search.

I hope this helps. Thanks for asking.