Leave trade, suffering, holding in pressure (6)
I believe the answer is:
depart
'leave' is the definition.
(I know that depart is a kind of leave)
'trade suffering holding in pressure' is the wordplay.
'suffering' is an anagram indicator.
'holding in' means one lot of letters goes inside another.
'pressure' becomes 'p' (abbreviation).
'trade' is an anagram of 'deart'.
'deart' enclosing 'p' is 'DEPART'.
(Other definitions for depart that I've seen before include "Go away or leave" , "Prated (anag.)" , "Set out" , "Start out" , "Leave (6)" .)