Take lower road in principle (6)
I believe the answer is:
rustle
'take' is the definition.
(thesaurus)
'lower road in principle' is the wordplay.
'lower road' becomes 'st' (I am not sure about the 'lower' bit.).
'in' is an insertion indicator.
'principle' becomes 'rule' (synonyms).
'st' put inside 'rule' is 'RUSTLE'.
Can you help me to learn more?
(Other definitions for rustle that I've seen before include "Wind-in-leaves noise" , "Dry crackling sound" , "Whisper softly" , "making little noise" , "Steal cattle or livestock with whispering sound" .)