They collect fares, starting tomorrow, on the Central line (5)
I believe the answer is:
taxis
'they collect fares' is the definition.
The definition suggests an adverb but the answer is not.
'starting tomorrow on the central line' is the wordplay.
'starting' says to take the initial letters.
'on' is a charade indicator (letters next to each other).
'the central line' becomes 'axis' (I've seen this in another clue).
The first letter of 'tomorrow' is 't'.
't'+'axis'='TAXIS'
Can you help me to learn more?
(Other definitions for taxis that I've seen before include "Cabs" , "Cars with a driver for hire" , "return to right place" .)