Gather from single answer (5)
I believe the answer is:
glean
'gather' is the definition.
(I know that glean is a more specific form of gather)
'from single answer' is the wordplay.
'from' indicates a hidden word.
'GLEAN' is hidden within 'single answer'.
(Other definitions for glean that I've seen before include "Angle (anag.)" , "Gather (grain) after a harvest" , "Gather remnants of corn" , "Gather, pick up" , "Gradually put together" .)