A thing - clear it out (7)
I believe the answer is:
article
'a thing' is the definition.
(I've seen this before)
'clear it out' is the wordplay.
'out' is an anagram indicator (out can mean wrong or inaccurate).
'clear'+'it'='clearit'
'clearit' is an anagram of 'ARTICLE'.
(Other definitions for article that I've seen before include "Rile cat (anag.)" , "Eg, a, an or the" , "Feature - item" , "Newspaper piece" , "Commodity" .)