Answer (5)

'answer' is the definition.
(I know that answer is a more specific form of the action react)
This is all the clue.
(Other definitions for react that I've seen before include "provide an answer" , "What a chemical might do" , "Show opposition" , "Change chemically" , "Behave in response" .)
'answer' is the definition.
(I know that answer can be written as reply)
This is all the clue.
(Other definitions for reply that I've seen before include "Reciprocate" , "Come back" , "Comeback" , "response is demanded" , "Return" .)
'answer' is the definition.
(I know that answer can be written as solution)
This is all the clue.
(Other definitions for solution that I've seen before include "Homogeneous mixture" , "Drink" , "may involve a certain concentration" , "Key" , "Elucidation - mixture of substances" .)
'answer' is the definition.
(I know that answer can be written as response)
This is the entire clue.
(Other definitions for response that I've seen before include "counter" , "Reply, rejoinder" , "Sees porn (anag) - answer" , "Press one for a reply" , "bid by partner" .)
'answer' is the definition.
(I know that answer can be written as respond)
This is all the clue.
(Other definitions for respond that I've seen before include "Answer or react" , "State in reply" , "Write back" , "Answer back" , "Reply - react" .)