look up any word, like spook:
 
1.
A person who will be beaten up in a severe manner.
Someone needs to tell that person to get out of my face before they get flexed.
by Lemuel Williams June 02, 2003
 
2.
1. To get hurt, flogged, fucked up and shit. From a bashing with fists to getting knackered on a rail while skateboarding.
2. To be fucked up on drugs or liquor.
1. "I tried a Backside 7 on my snowboard of that gap and fully flexed myself."
2. "I did that? Really? I must have been flexed last night."
by Diego August 10, 2003
 
3.
Deep ass fucking by a huge dick.
I flexed her asshole so hard it tore.
by Jakeypoo97 May 29, 2013
 
4.
to have "dealt" with, or went out, dated.
i have flexed with 6 guys so far in my whole life.
by kaanybaby February 28, 2009