In market, gold rings good for high-flier (7)
I believe the answer is:
seagull
'flier' is the definition.
(seagull is a kind of birdanimal)
'in market gold rings good' is the wordplay.
'in' is an insertion indicator.
'market' becomes 'sell' (I've seen this in another clue).
'gold' becomes 'Au' (Au is the chemical symbol for gold).
'rings' means one lot of letters goes inside another (some letters are ringed or contained by others).
'good' becomes 'g' (abbreviation).
'au' enclosing 'g' is 'agu'.
'sell' enclosing 'agu' is 'SEAGULL'.
'for high' is the link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for seagull that I've seen before include "Bird paradoxically fond of landfill sites" , "Main creature" , "One sitting atop mast perhaps" , "Avian scavenger" , "Marine bird" .)