Left a fleet developing some advertising (7)
I believe the answer is:
leaflet
'some advertising' is the definition.
The answer and definition can be both related to communication as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'left a fleet developing' is the wordplay.
'left' becomes 'l' (common abbreviation).
'developing' indicates anagramming the letters (letters developed into a new form).
'a'+'fleet'='afleet'
'afleet' is an anagram of 'eaflet'.
'l'+'eaflet'='LEAFLET'
Can you help me to learn more?
(Other definitions for leaflet that I've seen before include "Flyer, bill" , "Advertising sheet" , "Sheet of paper giving information" , "Single printed sheet" , "Handbill, flyer" .)