Eager to gather round duck (5)
I believe the answer is:
avoid
'duck' is the definition.
(duck can mean to avoid)
'eager to gather round' is the wordplay.
'eager' becomes 'avid' (synonyms).
'to gather' means one lot of letters goes inside another.
'round' becomes 'o' (round can mean a round object).
'avid' placed around 'o' is 'AVOID'.
(Other definitions for avoid that I've seen before include "Get out of" , "Sidestep" , "Desist" , "Keep away from (someone/something)" , "Shun, dodge" .)