Live way out guarding head of state (5)
I believe the answer is:
exist
'live' is the definition.
(synonyms)
'way out guarding head of state' is the wordplay.
'way out' becomes 'exit' (synonyms).
'guarding' indicates putting letters inside.
'head of' indicates taking the first letters.
The first letter of 'state' is 's'.
'exit' enclosing 's' is 'EXIST'.
(Other definitions for exist that I've seen before include "Get a life!" , "quick!" , "Scrape by" , "Survive" , "Be alive" .)