Like the slimmer's chance of being sylph-like? (7)
I believe the answer is:
slender
'sylph-like?' is the definition.
(synonyms)
'like the slimmer's chance of being' is the wordplay.
I cannot really see how this works, but
'being' could be 'lender' (lender is a kind of being) and 'lender' is found in the answer.
A single letter 's' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for slender that I've seen before include "Feeble" , "Gracefully slim" , "Willowy" , "Fine" , "Meagre" .)