mainline

(n) The front-running leader(s) of an industry; not the imitation spin-offs. Reserved for the select few whom others try to imitate albeit never successfully. If you are not mainline you are hopeless and should probably just quit what you do, now.

(adj) Describing an action that would only be done by someone/something that is mainline.

Guy 1: Why does that guy drive such a shitty old car if he's a lawyer?

Guy 2: He must not be mainline. If he were, he would drive a BMW 5 Series.

*******
Guy 1: Lebron James is overrated.

Guy 2: Seriously?! He is the most mainline basketball player of this generation.

by Reacharoundartist May 22, 2010

mainline

Weaponized wireless telepathic communications and informations system used by covert US military-intelligence in the Targeted Individual program.

The military had their own voice-to-skull...they called it the mainline... it was voice-to-skull.

by Medicine Owl February 08, 2023

Mainlining

The act of binge-watching or binge-listening all episodes of a podcast or all episodes in a season of a TV show without breaking for sleep.

Mackey: Where were you last night?
Buddy: Aw, man, I was mainlining "Sense8." After the second episode, I was addicted!

by GypsyBowl July 05, 2015

Mainline

A person's main significant other, even though they may be dating several people at once.

"I got a lot of chicks, I ain't gotta lie. But you keep it real, so you my mainline." - Ray Vicks

by BRNOLA July 13, 2009

SMT Mainline

A Canadian Youtuber who is known for his model train content and taking shots of maple syrup he is also allegedly a foamer

Did you see SMT Mainline’s video of that CP heritage Unit

by MinnesotaModelRailfan August 05, 2020

mainline mom

Goes to country club, wears lululemon tennis skirts. Everything is Vineyard Vines and Monograms. Cadalak SUV and marries older rich husbands.

You are a mainline Mom

by Tomrocks February 25, 2018

Jack the mainline

Doing heroin intravenously in the style of Robbie Williams. See also rock the mainline.

From Robbie Williams' "Rudebox":

"Ok then check the tan line
Make your body shape
Like you're stood on a landmine
Call me on my mobile
Not the landline
And jack the mainline
At the same time"

by Some Fresh Money September 08, 2007