Pause at small cracks (6)
I believe the answer is:
breaks
'cracks' is the definition.
(I know this)
'pause at small' is the wordplay.
'pause' becomes 'break' (synonyms).
'at' is a charade indicator (letters next to each other).
'small' becomes 's' (abbreviation - e.g. clothes size).
'break'+'s'='BREAKS'
(Other definitions for breaks that I've seen before include "Intervals" , "Shatters" , "stretches between lessons" , "Rest periods" , "Fractures or splits" .)