Come and go as bird around empty chick (7)
I believe the answer is:
flicker
'come and go' is the definition.
I can't tell whether this defines the answer.
'bird around empty chick' is the wordplay.
'bird' becomes 'flier' (I can't explain this - if you can you should believe this answer much more).
'around' is an insertion indicator.
'empty' means to remove the middle letters.
'chick' with its centre taken out is 'ck'.
'flier' enclosing 'ck' is 'FLICKER'.
'as' acts as a link.
Can you help me to learn more?
(Other definitions for flicker that I've seen before include "Spark" , "Glimmer" , "Burn or shine unsteadily" , "Twinkle" , "Vary rapidly in brightness" .)