Work requirement, say (5)
I believe the answer is:
knead
'work' is the definition.
('knead' can be a synonym of 'work')
'requirement say' is the wordplay.
'requirement' becomes 'need' ('need' can be a synonym of 'requirement').
'say' indicates a 'sounds like' (homophone) clue.
'need' sounds like 'KNEAD'.
(Other definitions for knead that I've seen before include "Work dough or massage flesh" , "Somehow work in" , "Massage with hands" , "Work with finger movements" , "Work (dough/clay)" .)