This indicates caution among chamberlains (5)
I believe the answer is:
'this indicates caution' is the definition.
The definition suggests a singular noun which matches the answer.
'among chamberlains' is the wordplay.
'among' says the answer is hidden in the clue.
'AMBER' is hidden in the letters of 'chamberlains'.
Can you help me to learn more?
(Other definitions for amber that I've seen before include "Cautionary light" , "Neither red nor green?" , "Fossil resin - warning light" , ""Stop" traffic light" , "Follilised resin" .)