Joy has cracked toenail (7)
I believe the answer is:
elation
'joy' is the definition.
(I know that elation is a type of joy)
'cracked toenail' is the wordplay.
'cracked' indicates an anagram.
'toenail' is an anagram of 'ELATION'.
'has' is the 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" .)