New moon about to be late (2,4)
I believe the answer is:
no more
'late' is the definition.
(thesaurus)
'new moon about' is the wordplay.
'new' indicates anagramming the letters.
'about' becomes 're' (regarding**).
'moon' is an anagram of 'nomo'.
'nomo'+'re'='NO MORE'
'to be' is the link.
(Other definitions for no more that I've seen before include "Never again, that's the lot" , "opposite of what Oliver wanted" , "Never again, that's the end of it" , "Like a dead parrot?" , "Monroe (anag)" .)