When you look next to you and see a guy getting road head, but the chick is so ugly you mistake her for a dog, or other hairy creature.
Guy 1: Hey isn't that Alan?
Guy 2: Yah, why does he have a dog on his lap?
Guy 1: That's no dog!!!!!
Guy 2: EEEWWWW!!! He is getting Road Dog!
A traveling companion that one is most often seen with.
Bill was hitting all the hot spots with his road dog, Tom.
A person going with you during your travels.
Guy#1. hey are you going to the national hobo gathering?
Guy#2. nah man I'm waiting for my road dog to get out of jail.
homies, best buddy, friend
yo roaddogg want to go chilled with the lady
a long haul truck driver
my husband is a road dog. he is away in his truck all week
Beers you drink in the car on the way home from a long day of work.
Man, I could go for a couple o' road dogs right about now.
Running buddies; people you hang out with, go to concerts with and in general, cause mayhem with. Good friends you can count on to head off on a road trip at the last minute.
Man, I miss my main road dogs Jim and Kristin. Remember the time we took off to Buckeye Lake and got lost? Good times.