It has one definition. Simply, wild, running wild out of control. REfering to your pit bull he is off his chain meaning he is out of control and could kill someone every body is freakin out. Same way with a killer party.
"Damb dude that fuckin bike is off the chain, wicked bike"
by leemer August 06, 2006
Starting back in the early 1800's when slavery in America was prevalent. When a nigger was or African American was on good behavior the slave master would unshackle the slave so they had a little freedom. This was widely accpeted as a "good thing" or "cutting loose" when the slave was let "off the chain" and now today we have many niggers saying thats off the chain and now you know where it comes from.
There you are Tobias, you are free to wonder about for a few hours. Johnson: "dang tobias you off the chain"
by bobdawg62488 October 21, 2009