Top definition
A person who's going on and on about a subject they're interested in, not letting others get a word in edgewise. By spewing a constant stream of information, they become the human equivalent of an open fire hydrant.
Jeez, Jon, you haven't stopped talking about 3D printing all night; you're being a real verbal fire hydrant!
by TheJanePlane June 03, 2015
Happy St. Patties Day!