Fashionable public transport making comeback (5)
I believe the answer is:
smart
'fashionable' is the definition.
('smart' can be similar in meaning to 'fashionable')
'public transport making comeback' is the wordplay.
'public transport' becomes 'trams' (I've seen this before).
'making comeback' shows that the letters should be reversed in order.
'trams' back-to-front is 'SMART'.
(Other definitions for smart that I've seen before include "Intelligent; sting" , "Sting - witty" , "Fashionable" , "Trams (anag.)" , "Clean, tidy; clever" .)