踏破鐵鞋無覓處 [－－铁－无觅处]

Jyutping daap6 po3 tit3 haai4 mou4 mik6 cyu3
Pinyin tà pò tiě xié wú mì chù

Definitions (CC-CANTO)
  1. to describe something that is nowhere to be found even after painstakingly exhausting all of one's energy and effort to look for it
Definitions (Wiktionary)
  1. phrase, idiomatic
    One will search high and low only to find it when one least expects to.
Definitions (Kaifangcidian)
  1. （沒有對應漢語詞彙）