Ponders in order to make an appropriate reply (7)
I believe the answer is:
respond
'an appropriate reply' is the definition.
'respond' can be an answer for 'reply' (I've seen this before). I am unsure of the 'an appropriate' bit.
'ponders in order' is the wordplay.
'in order' indicates anagramming the letters (the letters in a new order).
'ponders' is an anagram of 'RESPOND'.
'to make' acts as a link.
Can you help me to learn more?
(Other definitions for respond that I've seen before include "Write back" , "Reply - react" , "React (positively) to a stimulus or treatment" , "Answer back" , "Come back" .)