Dolly left the French in Ilium (7)
I believe the answer is:
trolley
'dolly' is the definition.
(a dolly is a kind of wheeled trolley)
'left the french in ilium' is the wordplay.
'left' becomes 'l' (common abbreviation).
'the french' becomes 'le'.
'in' means one lot of letters goes inside another.
'ilium' becomes 'troy' ('Troy' can be a synonym of 'ilium').
'l'+'le'='lle'
'lle' placed within 'troy' is 'TROLLEY'.
(Other definitions for trolley that I've seen before include "Wheeled handcart" , "Collector of shopping" , "Yell rot (anag.)" , "Wheeled table, cart" , "American tram or supermarket purchases carrier" .)