Pressurise poor over working (6)
I believe the answer is:
leanon
'pressurise' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.
'poor over working' is the wordplay.
'poor' becomes 'lean'.
'over' is a charade indicator (letters next to each other) (in a down clue, some letters go over others).
'working' becomes 'on' (e.g. a machine is working or on).
'lean'+'on'='LEANON'
Can you help me to learn more?
(Another definition for leanon that I've seen is " Coerce".)