屁股頭 [－－头]

Jyutping pei3 gu2 tau4
Pinyin pì gu tóu

Definitions (Wiktionary)
  1. noun, Shanghainese-Wu
    rear, butt; the rear of a pair of trousers
  2. prep, Shanghainese-Wu
    behind a person
    (syn.) 屁股后头, 屁股後頭