Frightened swimmer imprisoned by the Poles! (6)
I believe the answer is:
shaken
'frightened' is the definition.
Both the definition and answer are adjectives. Perhaps they are linked in a way I don't understand?
'swimmer imprisoned by the poles' is the wordplay.
'swimmer' becomes 'hake' (hake is a kind of aquatic vertebrate).
'imprisoned by' indicates putting letters inside.
'the poles' becomes 'sn' (North and South poles).
'hake' placed into 'sn' is 'SHAKEN'.
Can you help me to learn more?
(Other definitions for shaken that I've seen before include "Shocked or agitated" , "Shocked; astonished" , "Disturbed like cocktail?" , "James Bond likes his martini this way" , "Shocked; brandished" .)