Deliberately open: pours out (2,7)
I believe the answer is:
on purpose
'deliberately' is the definition.
(synonyms)
'open pours out' is the wordplay.
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'open'+'pours'='openpours'
'openpours' anagrammed gives 'ON PURPOSE'.
(Other definitions for on purpose that I've seen before include "Deliberately, intentionally" , "Oppose run with deliberate intention" , "Pours open - quite deliberately (2,7)" , "Deliberately, not by chance" , "Deliberately, with firm intent (2.7)" .)