Someone who is young, plump, annoying and desperate to please.
Derived from the word 'oblong', for no particular reason.
Young girl : "Hey! hey! hey! guess what! i got the new backstreet boys cd! do you like the backstreet boys? i think theyre great! i think nick is the hottest... who do you like???"
Me : "Shut up oblo"
Young girl : "Dont call me that!"