Red-lighting/to red-light is to draw unwanted attention to yourself or another person, usually when committing a criminal act or trying to get away with something shady.

You risk red-lighting yourself &/or another person by behaving in a manner that may elicit unwanted scrutiny.

In Australia the saying is usually used by those who have a criminal background and tends to be associated with people from that demographic.

Examples;
Sitting in a car for an extended period of time when waiting to score.
Being under the influence when dealing with authority figures.

Engaging in avoidable, often pointless activities that put a person at risk of discovery when they would otherwise be in a position to evade notice such as;
driving a few km over the speed limit, using your mobile while driving, stealing something trivial, engaging in unnecessary conflict (verbal or otherwise), littering and so on.
"Mate, I ended up red-lighting myself something bad waiting for Jimbo to show."

"You're just going to red-light yourself driving to Springvale in that car."
by Slim Crim January 12, 2019
The act of hallucinating without the use of psychoactive drugs, such as LSD or acid. This requires one ping pong ball, a radio with headphone jack, and a red lightbulb. To hallucinate, cut the ping pong ball in half and tape halves over eyes. Then turn the radio to a white noise (static) station and put on headphones. Finally, stare into red lightbulb and wait for about half an hour. Soon, you will start to hallucinate.
Greg: Where were you man? We we're gonna watch the game!

Ben: I was at home, red-lighting. I rode a unicorn underwater.

Greg: That explains why you didn't text back.
by rugger26 April 25, 2011
The moment just prior to having uncontrollable diarrhoea. A red light gives you approximately 10 seconds to make it to the bathroom before wherever you are becomes ground zero for a "pooclear" explosion.
I was on the train to work this morning when without warning I got a red light and some fucker was in the bathroom! I had no choice but to go in the sink!
by braceyajax April 23, 2010
A game played by two people where player 1 puts their hand up player 2's pants, if player 2 gets uncomfortable they say "red light," this means player 1 wins. If player 1 gets uncomfortable and takes their hand out of player 2's pants, player 2 wins. If player 1 touches player 2's genitals, it is considered a draw.
Player 1: Want to play 'Red Light'
Player 2: sure!
(Player 1 slowly moves their hand up player 2's pants until they are just about to touch their scrotum)
Player 2: RED LIGHT!!!
(Even though player 1 has won they continue and end up giving player 2 a handjob)
by Porn54 March 17, 2017
A way of telling someone to be quiet, or shut up. Or it can be used a way to interrupt.
*Girl Talking Shit*
Girl 1 - OMG. She's such a slut, like I would kick her ass.
Girl 2 - I'm going to have to red light you real quick. Stop talking shit.

OR.
*Two males in fight*
Guy - Is it a scrap? Like what's good? Nize it.
Guy 2 - Nize it? RED LIGHT, RED LIGHT. Come at me then.
by IgnoranceIsBlissTHO February 23, 2012
“I changed my LED lights to red lights because it’s so fitting for when I’m horny
by 333stone October 5, 2020