Compartment for passenger's drink (7)
I believe the answer is:
sidecar
I believe this is a double definition.
'compartment for passenger's' is the first definition.
(eg a motorcycle sidecar)
'drink' is the second definition.
(sidecar is a kind of drink)
(Other definitions for sidecar that I've seen before include "Vehicle" , "Appendage to motor cycle" , "Alcoholic drink" , "Motorcycle add-on" , "Attachment on motorcycle to carry passenger" .)