Lead in, lead out, insert paper and leave only sides (8)
I believe the answer is:
preamble
'leave only sides' is the definition.
The definition and answer can be both related to communication as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'lead in lead out insert paper' is the wordplay.
I cannot quite see how this works, but
'paper' could be 'ream' (I've seen this before) and 'ream' is located in the answer.
'lead' could be 'pb' (Pb is the chemical symbol for lead) and 'pb' is found within the leftover letters.
This explanation may well be incorrect...
'and' acts as a link.
Can you help me to learn more?
(Other definitions for preamble that I've seen before include "Preliminary or introductory statement" , "the first thing one reads?" , "Explanatory foreword" , "Make introduction" , "Introductory explanation" .)