Adjective, meaning of indeterminate origin, random scope, or just not clearly defined. Probably a contraction of "jabber" and "taboo", suggesting equal parts slander and salacious intent. However, one suggestion is that it's a jaboo re-arrangement of "jao bo", a loose Mandarin to English transliteration of the equally random and indeterminate "dog stick", making "jaboo" self-referential term in the spirit of "GNU".
"That was a jaboo dress. Did she think this party was some crap event?"