King in dodgy rodeo cheated (6)
I believe the answer is:
rooked
'cheated' is the definition.
(rooking is a kind of cheating)
'king in dodgy rodeo' is the wordplay.
'king' becomes 'K' (abbreviation for king in chess).
'in' is an insertion indicator.
'dodgy' indicates anagramming the letters (a dodgy or wrong order of the letters).
'rodeo' anagrammed gives 'rooed'.
'k' inserted within 'rooed' is 'ROOKED'.
(Other definitions for rooked that I've seen before include "gets done" , "Fleeced" .)