Old first to be present (5)
I believe the answer is:
exist
'be present' is the definition.
(thesaurus)
'old first' is the wordplay.
'old' becomes 'ex'.
'first' becomes 'ist'.
'ex'+'ist'='EXIST'
'to' is the link.
(Other definitions for exist that I've seen before include "Have objective reality" , "Live" , "Scrape by" , "Be alive" , "Survive" .)