Near in the clear - until tomorrow (9)
I believe the answer is:
overnight
'until tomorrow' is the definition.
(I've seen this before)
'near in the clear' is the wordplay.
'near' becomes 'nigh' (similar in meaning).
'in' is an insertion indicator.
'the clear' becomes 'overt' (both can mean apparent or obvious).
'nigh' inserted inside 'overt' is 'OVERNIGHT'.
(Other definitions for overnight that I've seen before include "Very quickly" , "darkness" , "until tomorrow" , "Lasting from dusk to dawn" , "from one day to the next" .)