mainline 

To inject a drug, usually heroin, into a vein. Also used to refer to the drug itself.

"That chick was mainlining heroin daily till she OD'd."

From Queensryche - Operation Mindcrime:

"Had a habit doing mainline
Watch the dragon burn
No regrets, you've got no goals
Nothing more to learn"

mainline by eidolon July 17, 2004

MainLine 

to render righteousness with perfect fidelity, especially using emerging information and communication technologies. A MKULTIMATE asset commandeered from MKULTRA.

During MKULTRA, every mainline was murder; now, we are fortunate to be able to MainLine America; now, every MainLine is a Miracle.

MainLine by Medicine Owl February 8, 2023

Mainline 

To watch a large amount of a geeky television show, episode after episode, for a long period of time. A season of Buffy in two days, for example.

Similar to marathoning movies or chain smoking, but more geeky.

"I just mainlined the first 3 seasons of Angel"

"I'm going to go home and mainline the LOTR movies."

"Wheres Ferg at?"
"Oh, hes at home, sitting in the dark, mainlining Simpsons episodes"

Mainline by Anna Heavens January 27, 2009

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.

mainline 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.

mainline by Medicine Owl February 8, 2023

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

Mainline by BRNOLA July 12, 2009

Mainline 

A group of fucksticks that smell like your uncles rotten ass and they all fight like a pack of rabid badgers over which idiot knows the most about a fucking fan clutch

I'd sure hate to be working on mainline

Mainline by Conkysbadlovelife April 16, 2024