Road not travelled by twister (7)
I believe the answer is:
tornado
'twister' is the definition.
(term for a tornado)
'road not travelled' is the wordplay.
'travelled' indicates anagramming the letters.
'road'+'not'='roadnot'
'roadnot' anagrammed gives 'TORNADO'.
'by' acts as a link.
(Other definitions for tornado that I've seen before include "Violent wind storm" , "A major blow" , "Cyclone, twister" , "Whirling storm" , "wind-up" .)