Road not affected by typhoon (7)
I believe the answer is:
tornado
'typhoon' is the definition.
(thesaurus)
'road not affected' is the wordplay.
'affected' indicates an anagram.
'road'+'not'='roadnot'
'roadnot' with letters rearranged gives 'TORNADO'.
'by' acts as a link.
(Other definitions for tornado that I've seen before include "threat" , "Windy hazard" , "Destructive weather" , "RAF fighter; whirlwind" , "Destructive wind vortex" .)