Like outside charge to ring-shaped reefs (6)
I believe the answer is:
atolls
'ring-shaped reefs' is the definition.
'atolls' can be an answer for 'reefs' (atoll is a kind of reef). I am not certain of the 'ring-shaped' bit.
'like outside charge' is the wordplay.
'like' becomes 'as'.
'outside' indicates putting letters inside.
'charge' becomes 'toll' (toll is a kind of charge).
'as' going around 'toll' is 'ATOLLS'.
'to' is the link.
Can you help me to learn more?
(Other definitions for atolls that I've seen before include "Ring-shaped coral reefs enclosing lagoons" , "Ring-shaped coral islands" , "Coral reef islands" .)