悉尼老鼠 [－－－－]

Jyutping sik1 nei4 lou5 syu2
Pinyin xī ní lǎo shǔ

Definitions (粵典–words.hk)
  1. 語句
    「​識​你​老鼠​」​嘅​諧​音​。​詳見識​⋯​老鼠
    expression of dismissiveness towards someone; literally: Sydney mouse, a word play on "識你老鼠" (sik1 nei5 lou5 syu2), which means "nobody knows who you are".