Ring back about island flower (5)
I believe the answer is:
lilac
'island flower' is the definition.
'lilac' can be an answer for 'flower' (I've seen this before). I'm unsure of the 'island' bit.
'ring back about' is the wordplay.
'ring back' becomes 'lila' (I can't justify this - if you can you should believe this answer much more).
'about' becomes 'c' (abbreviation for 'circa').
'lila'+'c'='LILAC'
Can you help me to learn more?
(Other definitions for lilac that I've seen before include "Pale mauve colour for a flower" , "Fragrant, pale purple flower" , "Fragrant,purple flower" , "Light purple - flowering tree" , "Shrub with fragment purple or white flowers" .)