Terminate construction breaks following working unrest (12)
I believe the answer is:
fermentation
'unrest' is the definition.
('fermentation' can be a synonym of 'unrest')
'terminate construction breaks following working' is the wordplay.
'construction' indicates anagramming the letters (answer constructed from certain letters).
'breaks' indicates putting letters inside.
'following' becomes 'f' (used when citing page numbers etc**).
'working' becomes 'on'.
'terminate' is an anagram of 'ermentati'.
'f'+'on'='fon'
'ermentati' going within 'fon' is 'FERMENTATION'.
(Other definitions for fermentation that I've seen before include "Process involving yeast" , "Yeast action" .)