Curse lone working in yard (9)
I believe the answer is:
enclosure
'yard' is the definition.
(thesaurus)
'curse lone working' is the wordplay.
'working' is an anagram indicator.
'curse'+'lone'='curselone'
'curselone' anagrammed gives 'ENCLOSURE'.
'in' is the link.
(Other definitions for enclosure that I've seen before include "Pen" , "Area fenced off - one's ulcer (anag)" , "compound" , "Sealed-off area" , "something to accompany letter?" .)