Be the leader of the stampede in the egress (5)
I believe the answer is:
exist
'be' is the definition.
(I know that be can be written as exist)
'leader of the stampede in the egress' is the wordplay.
'leader of' indicates taking the first letters.
'in the' indicates putting letters inside.
'egress' becomes 'exit' (I've seen this in another clue).
The initial letter of 'stampede' is 's'.
's' placed within 'exit' is 'EXIST'.
'the' acts as a link.
(Other definitions for exist that I've seen before include "Get a life!" , "quick!" , "Have being or continue living" , "Survive" , "Be alive" .)