Room in taxi back (5)
I believe the answer is:
cabin
'room in taxi back' is the definition.
'cabin' can be an answer for 'room' (cabin is a kind of room). I am not sure about the 'in taxi back' bit.
'room in' is the wordplay.
'room' becomes 'cab' (cab is a kind of room).
'cab'+'in'='CABIN'
Can you help me to learn more?
(Other definitions for cabin that I've seen before include "Small house (built of logs?)" , "Small room or hut" , "Lodge or hut" , "Hut or bothy" , "Compartment on a ship" .)