Disease resulting from awkward situation in car smash (7)
I believe the answer is:
cholera
'disease' is the definition.
(cholera is a kind of disease)
'awkward situation in car smash' is the wordplay.
'awkward situation' becomes 'hole' (I've seen this before).
'in' is an insertion indicator.
'smash' indicates an anagram.
'car' with letters rearranged gives 'cra'.
'hole' placed within 'cra' is 'CHOLERA'.
'resulting from' is the link.
(Other definitions for cholera that I've seen before include "Solemn promise" , "Infectious and often fatal Asiatic disease" , "serious illness" , "Disease contracted from infected water" , "A severe intestinal disease, severe Asiatic kind" .)