mumbo jumbo is gibberish

example: I don't understand you. Don't talk gibberish. 

Gibberish means nonsense, or no formal meaning.

down low =

anything you wish to keep a secret

example: 

Let's keep it down low. We don't want anyone to know about what really happened. 

sketchy

someone or something that 

is suspicious

example:

That guy, walking beside sarah looks sketchy. 

to crush - to fall asleep.

example: 

I'm so tired, I want to crush right away. 

9 to 5 

day job ,most corporate schedules begin at 9 am and end at 5pm 

example:

I'm on a 9 to 5. 

to vent - to complain about something in order to release stress

example:

Are you okay? vent it out. Stay relax and calmed. Everything will be okay. 

24/7 - 24 hours a day 

7 days a week

example: I work 24/7. 

to hang out - to relax 

with your friends

example:

I just want to hang out 

with my friends during the 

weekends.

The video is confusing. Avoid watching those type of videos it would just confuse you. Instead, start watching american news channels, as they are mostly neutral in accent and that they pronounce words well and most anchors have a well modulated voice which is good for learners. ^^ God bless. 

American Slang You Should Know

I tried to recognize all the slang words, idioms and definitions from the speech of this video http://www.youtube.com/watch?v=NczPRaHDlfQ
Please, correct my sentences.

jump the shark means something especially set come (?) private no longer (?)   sitcom, something that's past its prime and no longer relevant.
munchies (I have the munchies.) means hungry especially created food, junk food
(?) mamba jamba is duvresh  Mumbo Jumbo means gibberish, nonsense
dl is an acronym for down-low, saying anything you want to keep in a secret
(?) sketching sketchy means someone or something let to be suspections
(?) to beneath aeroll area [I don't know what she says here]
to crush To crash is to fall sleep
a nine to five is a day job and it's call the way because most of a BRITAINGES(?) called that way because most corporate jobs begin at 9am and end at 5pm
(?) avive A vibe is numperson is an impression by personal or place
(?) to went To vent is to complain about something or get really you stressed
24x7 means it something that's opened well 24 hours and 7 day per week
to hang out is to relax with your friends
a flick is a movie
digits usually for see is for someone's for number phone number. so if you ask someones for number you can say give me your digits
(?)ewall Awal as is the military expression for absoludatly  absence without leave, which means living leaving without permissions
(?)IMEI MIA is another military term and it means within action missing in action but often used in to will   another way, like my forest IMEI phone is MIA when you can find your phone
enjoy or backs me money  dough or bucks means money,

so thats realiest and all's will be okay 

So that's our list. I hope you have a really good day.

I highly suggest that you avoid watching videos like that. The girl did not have good pronunciation and it clearly confused you.

Best of luck!