1) (in real life) To give off some form of positive energy through vibes, beauty, etc. Most often used to describe how the person is perceived visually, like a smile but not something like a compliment.
a) To be close to or to break the TOS of a social media site in a way that is eye catching to some. Especially used if the action that caused the user to glow is something the community they are a part in often get criticized for.
b) To be suspected of being a federal agent who is either trying to infiltrate or provoke online communities. Often posted when an account is found to have doctored photos, made up first and last names, and/or relatively extreme ideas. Possibly a reference to the quote, "The cia ******* glow in the dark."
1) Becky: "How do I look?"
Samantha: "Omg, you're glowing!"
2)
a) User1: "All parents who vaccinate their children should have their children taken by Child Protective Services."
User2: "This man is glowing so hard."
b) User1: "If you're being interrogated by the police, I'd recommend to not invoke the right to remain silent because it looks more natural to the judge."
User2: "User1 is glowing so much, all of the images they've posted of themselves we're ripped from someone's abandoned blog from 2006 and nobody has been recorded in the US of having the same name they claim to have."
A governmental agent (FBI, NSA, CIA, ATF) making bait posts on forums and image boards to entrap individuals or gather intelligence. The purported goal of glowniggers is baiting potential criminals or gather intelligence about a particular online community to reveal their intentions or beliefs.
The practice of posting as a glownigger is called glowposting.
The term was coined by paranoid-schizophrenic internet personality and Temple OS programmer Terry Davis in his livestream. "The CIA niggers glow in the dark, you can see them if you're driving. You just run them over " - Terry Davis, 2017.
The term was popularized around 2018-2019 on 4chan.org (specifically the /pol/ board) and 8chan.