### Clue: Set down reservists in harbour (9)
### Answer: ENTERTAIN 
 ### Explanation: Definition: harbour
  [ENTER IN](to write or copy a record in writing,to set down) **containing**(…in) TA(abbrev. for $$T$$erritorial $$A$$rmy, the volunteer reserve force). 
Answer: To have in mind,harbour, eg. thoughts of being President.