... disturbed fish surrounded by poles (6)
I believe the answer is:
shaken
'disturbed' is the definition.
(synonyms)
'fish surrounded by poles' is the wordplay.
'fish' becomes 'hake' (type of fish).
'surrounded by' is an insertion indicator.
'poles' becomes 'sn' (North and South poles).
'hake' inserted inside 'sn' is 'SHAKEN'.
(Other definitions for shaken that I've seen before include "Upset or agitated" , "Flourished" , "Shocked; brandished" , "Upset - rattled" , "James Bond liked his martinis this way, not stirred" .)