Gap in continuity (6)
I believe the answer is:
hiatus
'gap in continuity' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for hiatus that I've seen before include "A break or gap in series or sequence" , "Interval" , "Pause or break in continuity" , "Brief respite" , "A lacuna or interruption" .)