Parisian in silence lying sprawled in charming manner (10)

'parisian in' is the definition.
Both the definition and answer are adverbs. Maybe there's a link between them I don't understand?

'silence lying sprawled in charming manner' is the wordplay.
I cannot really understand how this works, but
'silence' could be 'gag' (gagging is a kind of silencing) and 'gag' is found within the answer.
an anagram of 'lying' is 'ingly' which is within the answer.
The remaining letters 'en' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...

Can you help me to learn more?