One books into new hotel for a date? (5)
I believe the answer is:
ninth
'a date?' is the definition.
(I know that ninth is a type of date)
'one books into new hotel' is the wordplay.
'one' becomes 'i' (Roman numeral).
'books' becomes 'NT' (New Testament).
'into' means one lot of letters goes inside another.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'hotel' becomes 'h' (phonetic alphabet: alpha, bravo, charlie etc.).
'i'+'nt'='int'
'n'+'h'='nh'
'int' inserted inside 'nh' is 'NINTH'.
'for' acts as a link.
(Other definitions for ninth that I've seen before include "interval" , "One over the eighth" , "Third of a third" , "Beethoven's last?" , "Eg, Beethoven's choral symphony" .)