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!

No Bull Shit, and old hacker acronym which is usually used to signify that the talk will be serious.

The simple yet incredibly satisfactory act of walking round the block. It is the perfect thing to do when bored, and stimulates conversation, friendship and oddly also spontaneous dragon-baby abduction.
The fundamental rule of blocking is: do not retrace your steps!
Blocking also highly condemns the wearing of yellow socks.

In theatre, it is the act of setting the exact motions of each character in a scene and/or act. This occurs during rehearsal.

when one dude prevents another dude from gettin an easy girl, or blocking a player while hes using a flow to get a hot girl, mostly for one night stands, but rarely for relationships. also known as c0ck blocking