... book flight? (6)
I believe the answer is:
exodus
I believe this is a double definition.
'book' is the first definition.
(I know that Exodus is a book)
'flight' is the second definition.
(I know that exodus is a type of flight)
(Other definitions for exodus that I've seen before include "A mass departure, as in 2nd book of Old Testament" , "Second book of the Old Testament" , "Outgoing" , "Departure of the holy book" , "Departure of the Israelites from Egypt, led by Moses" .)