Require massage, we hear (4)
I believe the answer is:
need
'require' is the definition.
('need' can be a synonym of 'require')
'massage we hear' is the wordplay.
'massage' becomes 'knead' ('knead' can be a synonym of 'massage').
'we hear' shows a homophone (sound like).
'knead' is a homophone of 'NEED'.
(Other definitions for need that I've seen before include "Want - require(ment)" , "must have results!" , "destitute state" , "Cry out for - prerequisite" , "Exigency" .)