Pressure to divide excellent meal (6)
I believe the answer is:
supper
'meal' is the definition.
(supper is a kind of meal)
'pressure to divide excellent' is the wordplay.
'pressure' becomes 'p' (abbreviation).
'to divide' means one lot of letters goes inside another.
'excellent' becomes 'super' (I've seen this before).
'p' inserted within 'super' is 'SUPPER'.
(Other definitions for supper that I've seen before include "Light, late, meal" , "Eats late" , "has one had a few drinks?" , "Last meal of the day" , "Evening repast" .)