Pressure to show spirit right away (4)
I believe the answer is:
heat
This could be a double definition.
'pressure' is the first definition.
(I've seen this in another clue)
'spirit right away' is the second definition.
'heat' can be an answer for 'spirit' (thesaurus). I am not certain of the 'right away' bit.
'to show' is the link.
Can you help me to learn more?
(Other definitions for heat that I've seen before include "It's measured in therms" , "Cook" , "High temperature" , "Vehemence" , "Pressure" .)