Almost nobody here at midday (4)
I believe the answer is:
noon
'here at midday' is the definition.
(noon is the middle of the day)
'almost nobody' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'nobody' becomes 'no one' (not a single person).
'noone' with its last letter removed is 'NOON'.
(Other definitions for noon that I've seen before include "when PM starts" , "12 pm" , "See 8" , "12 o'clock" , "Twelve o'clock, midday" .)