I searched for the word 'morrow' and found out that it takes the definite article 'the'. It's an old word but still in use as I refer COCA. One of the example is:
the postbox by the door where it would not be noticed until the morrow
My question is,
'morrow' is a noun and so is 'tomorrow'. Both mean the same, but then why the word 'morrow' takes the definite article and 'tomorrow' does not! Say--
It is reserved till the morrow BUT
It is reserved tillthetomorrow.
If both mean the next day, and there should be only one day, 'the' seems okay with 'morrow' but not with 'tomorrow'.