Key rings? (6)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
atolls
'key rings?' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for atolls that I've seen before include "Ring-shaped coral reefs enclosing lagoons" , "Coral reef islands" , "Ring-shaped coral islands" .)