A classical type (5)
I believe the answer is:
'a classical type' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Maybe there's a link between them I don't understand?
This is all the clue.
Can you help me to learn more?
(Other definitions for alpha that I've seen before include "European character" , "Foreign character" , "Burrowing American rodent" , "Leading Greek character" , "starter" .)