Verb: To flex
Flexing is the voluntary act of bragging about an achievement or something one has. One may flex his property (such as money or jewelry), or his achievements (see example below) in order to feel superior to his peers and make them feel inferior, reassuring himself of his superiority.
Guy 1: Hey man, how did the test go?
Guy 2: I scored 70/100, how did you do?
Guy 1: Mh, 72/100, not bad not good.
Flexer: Haha! I scored 99/100 noobs!
Out of nowhere
Flexer: HEY GUYS, LOOK AT <insert valuable possession and/or personal achievement of dubious value>!
Tags: REDACTED DUE TO NOT WANTING TO BE ON AN FBI WATCHLIST Earrape, Incest...
OH FUCK THAT!