(Cantonese analogy) someone will lose half of something
Definitions (粵典–words.hk)
語句
歇後語，下半句係唔見一橛/噉橛 the former half of a sandwich pun, literally "to beat a dog with a cucumber", implying "to lose a section of something" (m4 gin3 jat1/gam2 gyut6)