Late, drove crazily - extremely unsafe (7)
I believe the answer is:
overdue
'late' is the definition.
(similar in meaning)
'drove crazily extremely unsafe' is the wordplay.
'crazily' is an anagram indicator.
'extremely' means to remove the middle letters.
'unsafe' with its middle removed is 'ue'.
'drove' is an anagram of 'overd'.
'overd'+'ue'='OVERDUE'
(Other definitions for overdue that I've seen before include "Beyond the designated time for payment" , "Belated" , "Behind schedule" , "Later than the appointed time, as for bill payment" , "Behind expected time" .)