Eager to be entitled to set out (7)
I believe the answer is:
earnest
'eager' is the definition.
(I've seen this before)
'be entitled to set out' is the wordplay.
'be entitled to' becomes 'earn' (I've seen this in another clue).
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'set' with letters rearranged gives 'est'.
'earn'+'est'='EARNEST'
'to' is the link.
(Other definitions for earnest that I've seen before include "Fervent - down payment" , "businesslike" , "Fixed" , "Serious - down payment" , "promise" .)