Condition of ground is v poor (7)
I believe the answer is:
proviso
'condition' is the definition.
(proviso is a kind of condition)
'ground is v poor' is the wordplay.
'ground' is an anagram indicator ('grind' the letters into a new form).
'is'+'v'+'poor'='isvpoor'
'isvpoor' with letters rearranged gives 'PROVISO'.
'of' acts as a link.
(Other definitions for proviso that I've seen before include "Clause in contract" , "Something insisted upon as part of an agreement" , "Condition, qualification" , "Condition added to an agreement" , "Requirement" .)