In retrospect, for example, even Ian Thorpe in the soup (6)
I believe the answer is:
potage
'soup' is the definition.
(I know that potage is a type of soup)
'in retrospect for example even ian thorpe' is the wordplay.
'in retrospect' is a reversal indicator.
'for example' becomes 'eg' (short for 'exempli gratia', 'for example' in Latin).
'even' indicates alternate letters (even-numbered letters are used).
'ian'+'thorpe'='ianthorpe'
The alternate letters of 'ianthorpe' are 'atop'.
'eg'+'atop'='egatop'
'egatop' backwards is 'POTAGE'.
'in the' is the link.
(Other definitions for potage that I've seen before include "French soup, usually thick" , "which is fairly thick" , "this spoon-fed?" , "that's thick" , "Thick, often creamy soup" .)