Avoid fish and fowl (8)
I believe the answer is:
duckling
'fowl' is the definition.
(duckling is a kind of fowl)
'avoid fish' is the wordplay.
'avoid' becomes 'duck' (ducking is a kind of avoiding).
'fish' becomes 'ling' (ling is a kind of fish).
'duck'+'ling'='DUCKLING'
'and' is the link.
(Other definitions for duckling that I've seen before include "Young swimmer" , "little fowl" , "Young mallard, for instance" , "Young swimming bird" , "Young waterfowl" .)