Go before and go back under pressure (7)
I believe the answer is:
precede
'go before' is the definition.
(I've seen this before)
'go back under pressure' is the wordplay.
I cannot quite understand how this works, but
'pressure' could be 'p' (scientific abbreviation) and 'p' is present in the answer.
'go back' could be 'recede' (I've seen this before) and 'recede' is found within the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
'and' acts as a link.
Can you help me to learn more?
(Other definitions for precede that I've seen before include "Go before (someone)" , "Come before (something)" , "Forerun" , "Walk in front of" , "Come or go before" .)