Somewhat powerless to embrace retreat in an enthusiastic manner (8)
I believe the answer is:
ardently
'somewhat powerless to embrace retreat' is the definition.
I can't tell whether this defines the answer.
'an enthusiastic manner' is the wordplay.
'an enthusiastic' becomes 'ardent' (I've seen this before).
'manner' becomes 'ly' (I can't justify this - if you can you should believe this answer much more).
'ardent'+'ly'='ARDENTLY'
'in' is the link.
Can you help me to learn more?
(Other definitions for ardently that I've seen before include "with zeal" , "In a very passionate way" , "With passion" , "full of enthusiasm?" , "Passionately" .)