European clad in new diamonds first (9)
I believe the answer is:
icelandic
'european clad in new diamonds first' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Perhaps you can see a link between them that I don't see?
'clad in new diamonds first' is the wordplay.
'new' indicates anagramming the letters.
'diamonds' becomes 'ice' (slang term for diamonds).
'first' is a charade indicator (letters next to each other).
'clad'+'in'='cladin'
'cladin' with letters rearranged gives 'landic'.
'landic' after 'ice' is 'ICELANDIC'.
Can you help me to learn more?
(Other definitions for icelandic that I've seen before include "Like many sagas" , "in island republic" , "Eg, native to Reykjavik" , "As European" , "Language of people of Reykjavik" .)