Eagle seen in sky holding, for instance, one flower (9)
I believe the answer is:
aquilegia
'flower' is the definition.
(I know that aquilegia is a type of flower)
'eagle seen in sky holding for instance one' is the wordplay.
'eagle seen in sky' becomes 'Aquia' (constellation in the shape of an eagle).
'holding' indicates putting letters inside.
'for instance' becomes 'leg' (I can't explain this - if you can you should believe this answer much more).
'one' becomes 'i' (Roman numeral).
'leg'+'i'='legi'
'aquia' placed around 'legi' is 'AQUILEGIA'.
(Other definitions for aquilegia that I've seen before include "Showy flower, also known as columbine" , "Bloomer" , "Plant also known as Granny's Bonnet" , "Flowering plant" .)