Humiliate a centre of operations (5)
I believe the answer is:
abase
'humiliate' is the definition.
(synonyms)
'a centre of operations' is the wordplay.
'centre of operations' becomes 'base' (I've seen this before).
'a'+'base'='ABASE'
(Other definitions for abase that I've seen before include "Humiliate" , "Humble (oneself)" , "Belittle, degrade" , "what 11 [REPRIMANDS] are meant to do" , "Lower" .)