Survey the whole lot with a girl (7)
I believe the answer is:
summary
'survey' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'whole lot with a girl' is the wordplay.
'whole lot' becomes 'sum' (I can't explain this - if you can you should believe this answer much more).
'with' means one lot of letters go next to another.
'a girl' becomes 'Mary' (girl's name).
'sum'+'mary'='SUMMARY'
'the' is the link.
Can you help me to learn more?
(Other definitions for summary that I've seen before include "Synopsis, outline" , "Immediate" , "Brief" , "Recapitulation" , "Arbitrary" .)