Lie in ditch, penned by wild hunt (7)
I believe the answer is:
untruth
'lie' is the definition.
(an untruth is a lie)
'ditch penned by wild hunt' is the wordplay.
'ditch' becomes 'rut' (rut is a kind of ditch).
'penned by' means one lot of letters goes inside another.
'wild' indicates anagramming the letters.
'hunt' is an anagram of 'unth'.
'rut' inserted into 'unth' is 'UNTRUTH'.
'in' is the link.
(Other definitions for untruth that I've seen before include "product of Orwell's ministry?" , "Fib" , "Fiction" , "A lie or false statement" , "Falsehood or lie" .)