Step over favourites (4)
I believe the answer is:
pets
'favourites' is the definition.
('pet' can be a synonym of 'favourite')
'step over' is the wordplay.
'over' says the letters should be written backwards.
'step' in reverse letter order is 'PETS'.
(Other definitions for pets that I've seen before include "Little darlings - step on them" , "Animals at home" , "Domestic animals" , "Domesticated animals" .)