Etonian squire involved in bit of market research (13)
I believe the answer is:
questionnaire
'bit of market research' 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?
'etonian squire involved' is the wordplay.
'involved' indicates an anagram (involved can mean confusing or complex).
'etonian'+'squire'='etoniansquire'
'etoniansquire' anagrammed gives 'QUESTIONNAIRE'.
'in' acts as a link.
Can you help me to learn more?
(Other definitions for questionnaire that I've seen before include "List of enquiries" , "Form for market research" , "List of inquiries" , "Survey answer sheet" , "Survey fill-in form" .)