Shotgun rider 

Most famously used in Tim McGraw's song "Shotgun Rider," this word means a person's partner in crime, best friend, and the person they want most riding shotgun in their car. No matter what life throws at them or the amount of time spent a part, they can pick right back up where they left off when they're together again. Because he don't want no other shotgun rider beside him, singin to the radio :)

*Shotgun Rider comes on the radio*
Brandon: Hey! You're like my shotgun rider.
Hannah: What's a shotgun rider anyways? Haha
Brandon: You don't know what a shotgun rider is??
Hannah: Nope
Brandon: Haha just listen to the song, and you'll get it.

*Brandon tries to sing the song back to her, but Hannah just laughs and smiles and starts to sing along too*

Shotgun rider by HannnahBannana5 June 16, 2015

Shotgun rider 

When you let your girlfriend sign her name in your front passenger seat binding her ownership to it so that even if you sell the vehicle the seat will be taken out and used as a redneck lawn ornament.

Jimmy: "Hey Billy Bob, I noticed that new chair ya got in the front yard."
Billy Bob: "Yup, that's my shotgun rider's seat from my old Ford pickup."
Jimmy: "Why'd ya take it out?"
Billy Bob: "She called dibs."

Shotgun rider by Phil Mahooterz May 26, 2015

ride shotgun 

1. To ride in the front passenger seat. The phrase is a direct allusion to the armed guard who sat beside the stagecoach driver
2. To keep a watchful eye on something or someone

Jon gets sick during long trips so he always prefers to ride shotgun

ride shotgun by WebC October 28, 2007