Joined two workers outside home (4,2,4)
I believe the answer is:
hand in hand
'joined' is the definition.
(thesaurus)
'two workers outside home' is the wordplay.
'two workers' can mean two replacements for 'worker'.
'worker' becomes 'hand'.
'worker' becomes 'hand'.
'outside' indicates putting letters inside.
'home' becomes 'in' ('he's home' can mean 'he's in').
'hand'+'hand'='handhand'
'handhand' placed around 'in' is 'HAND IN HAND'.
(Other definitions for hand in hand that I've seen before include "What whist players have" , "together" , "Jointly" , "Give back all one's cards" .)