Or a contraction of "Gazebo"
Possibly from an African language (Zulu or Swahili are often cited) word "M'khazi" meaning a latrine.
- carsey, carsy, karsey, karsy, karzey, karzy, kazi
khazi (plural khazis)
Particularly used in "down the khazi".
Khazi is now most commonly used in Liverpool, away from its cockney slang roots.