I shut a new opening (6)
I believe the answer is:
hiatus
'opening' is the definition.
(I've seen this before)
'i shut a new' is the wordplay.
'new' is an anagram indicator.
'i'+'shut'+'a'='ishuta'
'ishuta' is an anagram of 'HIATUS'.
(Other definitions for hiatus that I've seen before include "Interruption in intensity or amount" , "Gap in continuity" , "Pause; discontinuity" , "chasm" , "Break -- respite" .)