Smoker may need this to get off the bus (6)
I believe the answer is:
alight
'smoker may need this to get off the bus' is the definition.
'alight' can be an answer for 'to get' (thesaurus). I'm unsure of the remainder of the definition.
'smoker may need this to get off' is the wordplay.
I cannot quite understand how this works, but
'get off' could be 'light' (synonyms) and 'light' is located in the answer.
A single letter 'a' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for alight that I've seen before include "Come to rest on the ground" , "Get out of train" , "Brilliant" , "Dismount" , "Descend from vehicle" .)