Perhaps Armitage Shanks's third feature stops stool at opening in enamel (8)
I believe the answer is:
laureate
'perhaps armitage shanks's third feature stops' is the definition.
I can't tell whether this definition defines the answer.
'stool at opening in enamel' is the wordplay.
'stool' becomes 'laure' (I can't justify this - if you can you should give a lot more credence to this answer).
'opening in' suggests taking the first letters.
The first letter of 'enamel' is 'e'.
'laure'+'at'+'e'='LAUREATE'
Can you help me to learn more?
(Other definitions for laureate that I've seen before include "Honoured poet" , "Person honoured for great achievements" , "Person honoured for creative achievement" , "Outstanding achiever" , "This Poet is official in England" .)