### Clue: John's small piece of rope swapping hands (7)
### Answer: LATRINE 
 ### Explanation: Definition: John
 "ratline"(any of the small pieces of rope horizontally tied in a ship's rigging for climbing aloft) **with** "r","l"(abbrevs. for the right and left hands respectively) **changing places**(swapping …).
Answer: The slang for which is the "John".