### Clue: Not how Ko-Ko operates, lacking spirit (10)
### Answer: LISTLESSLY 
 ### Explanation: Definition: , lacking spirit
 LIST-LESS(without a list, contrary to;not how Ko-Ko, the Lord High Executioner, in Gilbert and Sullivan's The Mikado operates, declaring in his aria:
I've got a little list–I've got a little list
Of society offenders who might well be underground,
And who never would be missed–who never would be missed!
+ -LY(suffix forming adverbs from adjectives).
Defn: … as an adverbial phrase.