I lament terrible condition (7)
I believe the answer is:
ailment
'condition' is the definition.
(I know that condition can be written as ailment)
'i lament terrible' is the wordplay.
'terrible' indicates an anagram.
'i'+'lament'='ilament'
'ilament' with letters rearranged gives 'AILMENT'.
(Other definitions for ailment that I've seen before include "Tim Alen has an odd indisposition." , "I lament (anag.)" , "Sickness" , "problem" , "Physical disorder" .)