### Clue: Advanced engaging retreat with gusto (9)
### Answer: EARNESTLY 
 ### Explanation: EARLY(*advanced*,brought forward,nearer than the usual time.  A bit tricky, since advanced also means "gone, progressed further" as in eg. "advanced,late stages of cancer") around(*engaging*) NEST(*retreat*,some place to run to, eg. a love nest).  Defn:  *With gusto*, heartily.