... nobleman dividing New York almost (6)
I believe the answer is:
nearly
'almost' is the definition.
('nearly' can be a synonym of 'almost')
'nobleman dividing new york' is the wordplay.
'nobleman' becomes 'earl' (earl is a kind of nobleman).
'dividing' indicates putting letters inside.
'new york' becomes 'ny'.
'earl' going within 'ny' is 'NEARLY'.
(Other definitions for nearly that I've seen before include "More or less" , "Noon at eleven fifty nine am" , "Close" , "Almost, well-nigh" , "Not entirely" .)