Prominent foreigner in the way (7)
I believe the answer is:
salient
'prominent' is the definition.
(I know that prominent can be written as salient)
'foreigner in the way' is the wordplay.
'foreigner' becomes 'alien' (synonyms).
'in the' indicates putting letters inside.
'way' becomes 'st' (abbreviation for street).
'alien' placed inside 'st' is 'SALIENT'.
(Other definitions for salient that I've seen before include "Outstanding - it's lean (anag)" , "Foremost" , "Projecting outwards; significant" , "Prominent - in tales (anag)" , "Prominent, striking" .)