Pressure to consume fuel (4)
I believe the answer is:
peat
'fuel' is the definition.
(peat is a kind of fuel)
'pressure to consume' is the wordplay.
'pressure' becomes 'p' (abbreviation).
'to consume' becomes 'eat' (eating is a kind of consuming).
'p'+'eat'='PEAT'
(Other definitions for peat that I've seen before include "Some got energy from this" , "Partially carbonised vegetable matter used as a fuel when dried" , "Bog material" , "load of stuff in the garden?" , "Tape around turf" .)