Taken from the practice of leaving a car which has been thoroughly stripped up on concrete blocks. Something is said to be 'on blocks' when one comes back and finds it has been ransacked thoroughly.
I told you not to let anyone in--now my whole room's up on blocks!

Wait til Oscar gets back and finds his DVD collection up on blocks . . .
by Secret Agent Man September 18, 2003
Get the on blocks mug.
a term that proves to someone that you're not frontin. same as 'on mamaz' or 'on citas'. originated in the bay area
guy 1: let's put this shit down

guy 2: stop frontin'

guy 1: on blocks nigga
by fieldshityeee August 30, 2008
Get the on blocks mug.
A phrase referring to an occurrence of menstruation (i.e. being on your period).
"Cmon honey, I've been thinkin about that sweet ass all day..."
"I cant baby, Im on blocks"
"So?? We'll double up the naughty towel!"
by Olaf the Black May 15, 2009
Get the on blocks mug.
In the hood, when there's nobody outside.
Brisco: Hey Tyrone, y'all still hoopin today?
Tyrone: Nah man, its No block.
by Bama Slunn November 11, 2018
Get the No block mug.
The act of walking "around the block" without retracing your footsteps and always finishing where you started. You may only block where there is a path or a street so most people practice it in urban areas. Also, no blocker may ever wear yellow socks!
Let's go blocking.
by hairballfuzz September 16, 2012
Get the blocking mug.