A woman who is notorius for the way they get around, usually male virgins will loose their virginity to this woman and eventually move on to another woman.
"hey man i dont wanna graduate high school a virgin, so what do i do"
"hook up with Kaylin, shes a gateway chick, she will take care of you."
by somerandoman April 22, 2010
Believed to be Marijuana. But say, if marijuana did not exist, wouldn't that mean people would go directly to harder drugs? So say "if" marijuana is a gateway drug, that's not such a bad thing...
In a world without marijuana (Gateway drug)

Person 1: Hey man, wanna shoot some smack?

Person 2: Of course, it's too bad there isn't some magical herb we could smoke instead that slows people like us from getting to the real dangerous shit!!!

Person 1 & 2 shoot up.
by sebastiancee December 24, 2007
In gay culture: a relationship in which one partner is the other partner's first real homosexual partner, usually defined by one experienced partner and one non-experienced partner. The experienced partner usually helps the other person become okay with being homosexual and comfortable in homosexual relationships. This relationship almost always fails.
Matt: I don't know why you're with Bary.
Loyd: Because I like him.
Matt: Yeah, but it's totally a gateway relationship.
Loyd: I know, I'm setting myself up for heartbreak.
by firehotstud07 February 26, 2008
That one dick that if you messed with would lead down the slippery slope to more dicks.
"Dude, I would totally such my own dick if I could. I mean it's not gay if it's your own dick."

"No way man! I'm afraid my own dick would be the gateway dick."
by BCHam February 18, 2016
A gay individual whose mere presence encourages others to change their sexual orientation from heterosexual to homosexual or bisexual.
Hey you straight skater boy; be careful around Eric, he's a gateway gay. Try and keep your tongue in your mouth.
by Mizz Erica June 2, 2007
The first in a series of pranks between two parties. Essentially the opener to the war.

The Gateway Prank is typically something small such as saran wrapping a car. It is then followed by a bigger prank/act of vandalism thus starting a war between the two parties.
Dan and I drew some stuff on Amber's car last night. We had no clue it would be a Gateway Prank! I woke up and there was maple syrup and powdered milk all over my car!
by Alex Harm August 13, 2007
A guy who is cool and fun, but not hot enough. You get to know him and become friends with him. This friendship will then lead you to get introduced to his cool buddies and at least one or two of them might be hot.
I met this awesome guy. We really hit it off and I love hanging out with him, but I am not attracted to him. Yet, I am sure he has some cool friends and some of them are bound to be hot. He is totally my gateway guy!
by Elolabethen November 18, 2013