Talkative dear has answer for everything, initially (9)
I believe the answer is:
expansive
'talkative' is the definition.
(synonyms)
'dear has answer for everything initially' is the wordplay.
I cannot quite see how this works, but
'answer' could be 'ans' (abbreviation for answer) and 'ans' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for expansive that I've seen before include "Lavish" , "Talkative" , "Genial" , "Wide-ranging" , "Covering a wide area" .)