Bad start in passage (7)
I believe the answer is:
transit
'passage' is the definition.
(I know that passage can be written as transit)
'bad start in' is the wordplay.
'bad' indicates anagramming the letters.
'start'+'in'='startin'
'startin' with letters rearranged gives 'TRANSIT'.
(Other definitions for transit that I've seen before include "The process of going or passing - sic . . . . . . . gloria mundi" , "Conveyance of goods or people - tin star (anag)" , "In - - (en route)" , "Start in for the process of being conveyed" , "The act of carrying from one place to another" .)