### Clue: One is ill-at-ease when not working on this (4,5)
### Answer: SICK LEAVE 
 ### Explanation: Definition: this
  Cryptic defn: What one is on when ill and not working.  SICK(ill-at-ease) + LEAVE(what one is on when not working – could it be instead, LEAVE = to let alone,ease off?). I'm not sure about the definition and the explanation.