*Torch remains lit, initially missing in departure (6)
I believe the answer is:
flight
'departure' is the definition.
(thesaurus)
'torch remains lit initially missing' is the wordplay.
'torch remains' becomes 'fl' (I can't justify this - if you can you should give a lot more credence to this answer).
'lit' becomes 'tight' (I've seen this before).
'initially missing' means to remove the first letter.
'tight' with its initial letter taken away is 'ight'.
'fl'+'ight'='FLIGHT'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for flight that I've seen before include "Aviation" , "Air transport - running away" , "Exodus" , "The feathers on a dart or arrow" , "Air force unit; running away" .)