Breaks out first (5)
I believe the answer is:
rifts
'breaks' is the definition.
(I know this)
'out first' is the wordplay.
'out' is an anagram indicator.
'first' with letters rearranged gives 'RIFTS'.
(Other definitions for rifts that I've seen before include "Breaks, severances" , "Clefts in earth, or disagreements" , "Schisms" , "Clefts or fissures." , "differences ..." .)