Slogan created through chat (6)
I believe the answer is:
byword
'slogan' is the definition.
(thesaurus)
'through chat' is the wordplay.
'through' becomes 'by'.
'chat' becomes 'word' (I can't justify this - if you can you should give a lot more credence to this answer).
'by'+'word'='BYWORD'
'created' is the link.
Can you help me to learn more?
(Other definitions for byword that I've seen before include "Saw" , "One pointed at as exemplar" , "Person or thing spoken of as notable example" , "Memorable saying" , "Person or thing cited as a memorable example" .)