Floating duck acquired by shop for social worker (7)
I believe the answer is:
buoyant
'floating' is the definition.
(synonyms)
'duck acquired by shop for social worker' is the wordplay.
'duck' becomes 'o' (resembles zero - 'duck' in cricket).
'acquired by' means one lot of letters goes inside another.
'shop for' becomes 'buy' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'social worker' becomes 'ant' (ants are social insects).
'o' going within 'buy' is 'buoy'.
'buoy'+'ant'='BUOYANT'
Can you help me to learn more?
(Other definitions for buoyant that I've seen before include "Animated or floating" , "Cheerful, optimistic" , "Able to float" , "Tending to float" , "refusing to go to bed?" .)