Ubla is a word difficult to define however is used as a come back for those who dont have an extensive vocabulary. It is a word mostly used by hungover marias (lady muzzas) from the Western suburbs of Melbourne, against people from the Eastern Suburbs of Melbourne. Although it has originated between these two suburbs it is becoming more widely used.
An example of how the term Ubla can be used is when the Insultee (Eastern Person)calls the Maria (Western Person) a SNOB, and spells S.N.O.B the Maria defends herself by saying you are a U.B.L.A. This gives the maria more time to think of a better comeback while the insultee says huh whats ubla?