Zil/Zilla basically means brother or bro or bra for slang in Australia. Aussie slang from Perth Western Australia from a suburb in North-eastern suburbs off Beechboro. The words been around for a few years and slowly getting around the state. If its a chick (girl/woman) their called Xil or Xilla. The highest praise in the Z-unit nation is GodZilla second up would be MaddZil.
Zil 1. Oi zilla that chick over there looks proper bra.
Zil 2. uckin oath zil I ucked that xilla back in the dayz bra she went hardt.
Zil 1. My zilla, u a maddZil A, bra.
Zil/Zilla