Willingly have a new life (4)
I believe the answer is:
'willingly' is the definition.
(I've seen this in another clue)
'a new life' is the wordplay.
'a new' indicates an anagram.
'life' is an anagram of 'LIEF'.
'have' acts as a link.
(Another definition for lief that I've seen is " In old usage, gladly or willingly - file away".)