Car reverses over one; almost meat (5)
I believe the answer is:
bacon
'meat' is the definition.
(bacon is a kind of meat)
'car reverses over one almost' is the wordplay.
'car' becomes 'cab' (cab is a kind of car).
'reverses' shows that the letters should be reversed in order.
'over' is a charade indicator (letters next to each other).
'almost' means to remove the last letter (most of the word but not all of it).
'cab' back-to-front is 'bac'.
'one' with its final letter taken away is 'on'.
'bac'+'on'='BACON'
(Other definitions for bacon that I've seen before include "Salted and smoked pig meat" , "Author" , "Irish-born painter" , "successfully brought home" , "Processed pig-meat" .)