plug-ugly Share definition Flag A firefighter who in olden times would stand at the plug (essentially a hydrant) and beat off firefighters from competing companies. Now used to describe a salty type of pipeman. Mark's been a pipeman for 15 years, he's a real plug-ugly. plug-ugly by plug-ugly August 19, 2014 0 0 Get merch Get the plug-ugly mug. Buy Now — $32.95 See more merch