Body of water in city that is conversely smack in the middle (4,4)
I believe the answer is:
lake erie
'body of water' is the definition.
(Lake Erie is an example)
'city that is conversely smack in the middle' is the wordplay.
'city' becomes 'LA' (Los Angeles).
'that is' becomes 'ie' (abbreviation for id est, 'that is' in Latin).
'conversely' is a reversal indicator (in a converse direction).
'smack' becomes 'reek' (both can mean to smell).
'in the middle' means one lot of letters goes inside another.
'reek' backwards is 'keer'.
'la'+'ie'='laie'
'laie' going around 'keer' is 'LAKE ERIE'.
'in' acts as a link.
(Other definitions for lake erie that I've seen before include "lots of water" , "One of the five Great ones in North America" .)