Like the smell of burned rubber (5)
I believe the answer is:
acrid
'like the smell of burned rubber' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for acrid that I've seen before include "irritating" , "Having a bitter taste or small, like smoke" , "Pungent; caustic" , "Unpleasantly pungent" , "Bitter - caustic" .)