Joy has cracked toenail (7)
I believe the answer is:
elation
'joy' is the definition.
(elation is a kind of joy)
'cracked toenail' is the wordplay.
'cracked' indicates an anagram.
'toenail' with letters rearranged gives 'ELATION'.
'has' acts as a link.
(Other definitions for elation that I've seen before include "Feeling of joy from toenail" , "Toenail (anag) -- delight" , "Delight, thrill" , "Exaltation" , "There's great joy" .)