One who verbally masturbates his ego or mercilessly self-promotes. A jabobo will usually try to use language or knowledge that is confounding in order to make another believe that his own intellect is superior.

Someone who rocks, alot.
Also, A mix between 1: JABO, German term for a Fighter-Bomber, then we have, BOBO, which is spanish for stupid.

So, all in all, It means a Rocking, Spanish, Stupid, Fighter-Bomer.