Normally is the word used in the italian language to define the "stretcher" (i.e: he was carried away on a stretcher)
It has then become widely used with two particular meanings:
1. As a noun, "La Barella" is the italian slang for Cocaine (probably more in the north-west regions as Lombardy or Piedmont)
2. As a verb, means "freaking out", "getting wasted", being totally fucked up
1. Oh, zio, porta la barella ! - yo, bro, bring the cocaine
2. Zio, stai sbarellando di brutto !! - dude, you're freaking out of your goddamn mind!
3. Minchia Tony l'altro giorno ha sbarellato! - Fuck, Tony got really mad the other day
4. Ou, ripigliati che stai sbarellando - dude, you're losin it, get your shit 2gether
Barbarella is the best girl you'll ever meet. She's blazing hot, has awesome outfits, hangs out with aliens and she's overall as beautiful as "Wish You Were Here". She's also kind, loving and emotional. She's very musical and has a great voice (but if you take her to a club she'll be louder than the band itself). If you ever meet a Barbarella, you're one lucky bastard.
Dude 1: "Man, who's that? She lookes aaaweeesome"
Dude 2: "Oh, that's Barbarella, the chick that shagged every alien kn the galaxy"