Dreadful sort of ride (4)
I believe the answer is:
dire
'dreadful' is the definition.
(I know that dreadful can be written as dire)
'sort of ride' is the wordplay.
'sort of' is an anagram indicator.
'ride' anagrammed gives 'DIRE'.
(Other definitions for dire that I've seen before include "Really dreadful - ride on" , "Disastrous" , "Ominous; very bad" , "to speak (13) [FRENCH]" , "Ride in dreadful state" .)