It is an upper language class that you use when you want to sleep with someone.
And it is also used as an objection word to stop someone from talking or to make his words look silly.
Fake cocktail/drink. The word exists purely as a way of cracking a joke at a barperson's expense whilst your mates are standing round, thus guaranteeing you kudos for the rest of the evening.
For best effect, order a few normal drinks, then finish off by requesting a matabooboo.
The word originates from Yogi Bear's sidekick. See example for full usage and relevance details.
Donna: "Who's next?"
Wes: "Yeah, can I have 3 pints of Stella, two double vodka red bulls, a sex on the beach and a matabooboo".
Donna: "A what?"
Wes: "A matabooboo"
Donna: "What's a matabooboo"
Wes: "Nothing Yogi, what's the matter with you?"
Donna: "... knob."
Macaela is a person who acts innocent, but isn't always. She can be a little princess at time, by whinning, but she is a great friend. She is kind and gets along well with others. She can be hyper. If you like a Macaela, she would be a great girlfriend as well.
Friend(Kayla): Macaela, stop being a little princess.
Friend(Isabella): *laughs and falls over*
Macaela: I'm not a little princess! *whinny voice*
Kayla: Stop whinning then! And also you aren't so innocent...