Edginess is when you are being dark, mysterious and serious too much. Check Mayu's post.
Definition:
Intentional attempt at appearing dark, violent and mysterious, but more often than not, being quite the contrary.
Examples of being edgy:
?: "You do not know that I am here."
?: "..."
?: "I am hunted in three galaxies."
?: "Feel free to kill me... many tried, everyone fallen."
?: "I have like 10 reasons why I shouldn't listen to you writen in my notepad, but you're not worthy of either of them."
?: "Spare me the sob story, I'll shoot you in 2 minutes."
?: "Sugertits, no man is gonna listen to your depressing story. That's why you're all alone and soon to be a cat lady."
?: "I've only known pain my entire life, and my whole existence is a hellscape. I wish nothing but suffering on all of mankind, for their sins against me."
?: **stands mysteriously as his fedora is blown off by a gust of wind, a prop katana affixed to his back**
?: "Just try me. It might be the last thing you do."