Striking stranger blocking way (7)
I believe the answer is:
salient
'striking' is the definition.
(I know that striking can be written as salient)
'stranger blocking way' is the wordplay.
'stranger' becomes 'alien' (synonyms).
'blocking' is an insertion indicator (to block can mean to plug a gap in something).
'way' becomes 'st' (abbreviation for street).
'alien' going into 'st' is 'SALIENT'.
(Other definitions for salient that I've seen before include "Prominent, most noticeable" , "Prominent - in tales (anag)" , "part of defences" , "defence work" , "Projecting outwards; significant" .)