### Clue: Skilful Bill drained pint without spillage in the end (5)
### Answer: ADEPT 
 ### Explanation: Definition: Skilful
 [ AD(short for an advertisement, an example of which is the poster or bill) + "pint" **minus its inner letters**(drained …) ] **containing**(without) **last letter of**(… in the end) "spillage".