Surprised prostitute in vehicle with runners (8)
I believe the answer is:
startled
'surprised' is the definition.
(similar in meaning)
'prostitute in vehicle with runners' is the wordplay.
'prostitute' becomes 'tart' (synonyms).
'in' is an insertion indicator.
'vehicle with runners' becomes 'sled' (I've seen this in another clue).
'tart' put within 'sled' is 'STARTLED'.
(Other definitions for startled that I've seen before include "Shocked, alarmed" , "Affrighted" , "Surprised with fright" , "Taken aback" , "Scared" .)