Reply, respond (6)
I believe the answer is:
answer
I believe this is a double definition.
'reply' is the first definition.
(answer is a kind of reply)
'respond' is the second definition.
(I know that respond can be written as answer)
(Other definitions for answer that I've seen before include "What you need" , "It could give you a" , "Respond" , "fit" , "Solution (to problem)" .)