To call an end to a situation that is heading in a direction you don't like.
Usually used in a humorous manner to highlight that you don't approve of a situation
You and friends go to see a movie that turns out to be of poor quality or distasteful so as it gets to a particularly bad scene you call 'Shut it down' as you walk out.
2. Doing a thing the best, hardest, most full out that it can be done.
"I SHUT IT DOWN, HO!"
2. "What are your plans regarding the Lil Wayne concert tomorrow?
"I'M GOING TO SHUT IT DOWN!!!!!
"SHUT IT DOWN"
"I understand and will speak to you in detail tomorrow."
boonetta: girl you already know cece went in there and shut it down. ricky know what the deal is now.