Introduction of setter's site (10)
I believe the answer is:
imposition
'introduction' is the definition.
(thesaurus)
'setter's site' is the wordplay.
'setter's' becomes 'I'm' (I am - referring to the crossword setter).
'site' becomes 'position' (I can't justify this - if you can you should give a lot more credence to this answer).
'im'+'position'='IMPOSITION'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for imposition that I've seen before include "Unwelcome demand or burden" , "tax" .)