Observe rising anger in thoroughfare (6)
I believe the answer is:
regard
'observe' is the definition.
(I know that observe is a more specific form of fear)
'rising anger in thoroughfare' is the wordplay.
'rising' says the letters should be written in reverse (in a down clue, letters go up).
'anger' becomes 'rage' (rage is a kind of anger).
'in' indicates putting letters inside.
'thoroughfare' becomes 'rd' (abbreviation for road).
'rage' back-to-front is 'egar'.
'egar' inserted inside 'rd' is 'REGARD'.
(Other definitions for regard that I've seen before include "Look at - estimation" , "Look at - esteem" , "Relation to" , "Consider, view" , "Former gold coin" .)