Drollery good during early years, but ... (8)
I believe the answer is:
badinage
'drollery' is the definition.
(I've seen this before)
'good during early years but' is the wordplay.
I cannot really understand how this works, but
'good' could be 'g' (abbreviation) and 'g' is found within the answer.
'during' could be 'in' (I've seen this in other clues) and 'in' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for badinage that I've seen before include "joking" , "Frivolous banter" , "bit of playful repartee" , "Good-humoured banter (8)" , "Amiable banter" .)