To understand it, you must have a feeling for words (7)
I believe the answer is:
braille
'feeling for words' 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?
'to understand it you must have a' is the wordplay.
I cannot really understand how this works, but
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is found in the answer.
'a' is found in the answer.
The remaining letters 'brill' is a valid word which might be clued in a way I don't understand.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for braille that I've seen before include "Language read by touch" , "Print language for blind" , "System of writing for the visually-impaired" , "Liberal (anag) - reading system" , "Raised type for blind people" .)