Emphasise the pressure (6)
I believe the answer is:
stress
This clue is a double definition.
'emphasise' is the first definition.
(I know that emphasise can be written as stress)
'pressure' is the second definition.
(I've seen this in another clue)
'the' is the link.
(Other definitions for stress that I've seen before include "Cause of crack" , "possible excuse for sickie?" , "Pressure or strain" , "Highlight" , "why off work?" .)