Rake ultimately into French wine and crack (4)
I believe the answer is:
vein
'crack' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Maybe there's an association between them I don't understand?
'rake ultimately into french wine' is the wordplay.
'ultimately' suggests the final letters.
'into' is an insertion indicator.
'french wine' becomes 'vin' ('wine' in French).
The final letter of 'rake' is 'e'.
'e' going inside 'vin' is 'VEIN'.
'and' is the link.
Can you help me to learn more?
(Other definitions for vein that I've seen before include "Blood-vessel" , "Distinctive quality" , "Rock fissure or minerals therein" , "Vessel carrying blood towards the heart" , "Speaker's useless" .)