Boadicea's tribe preserved in ice, perhaps (5)
I believe the answer is:
iceni
'boadicea's tribe' is the definition.
(I've seen this in another clue)
'in ice perhaps' is the wordplay.
'perhaps' is an anagram indicator.
'in'+'ice'='inice'
'inice' with letters rearranged gives 'ICENI'.
'preserved' acts as a link.
This may not be correct. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for iceni that I've seen before include "East Anglian tribe of Britons" , "Ancient British tribe" , "Old warriors" , "people rebelling against Rome" , "Boudica's tribe" .)