Journalist tired out covering start of Open (6)
I believe the answer is:
editor
'journalist' is the definition.
(thesaurus)
'tired out covering start of open' is the wordplay.
'out' is an anagram indicator (out can mean wrong or inaccurate).
'covering' is an insertion indicator.
'start of' suggests taking the first letters.
The initial letter of 'open' is 'o'.
'tired' anagrammed gives 'editr'.
'editr' placed around 'o' is 'EDITOR'.
(Other definitions for editor that I've seen before include "One prepares a work for publication" , "Journalist - rioted (anag)" , "Person who determines the final content of a text" , "Source of leaders" , "Reviser" .)