Holiday without Romeo and Bill (4)
I believe the answer is:
beak
'bill' is the definition.
(I know that bill can be written as beak)
'holiday without romeo' is the wordplay.
'holiday' becomes 'break' (break can mean a holiday or time off).
'without' indicates named letters should be taken away.
'romeo' becomes 'r' (phonetic alphabet: alpha, bravo, charlie etc.).
'break' with 'r' taken out is 'BEAK'.
'and' acts as a link.
(Other definitions for beak that I've seen before include "Schoolmarm" , "Magistrate (informal)" , "Magistrate -- schoolmaster (old slang)" , "Judge - bill" , "Bill; nose" .)