Twelve? Almost nobody (4)
I believe the answer is:
noon
'twelve?' is the definition.
(twelve noon)
'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 final letter removed is 'NOON'.
(Other definitions for noon that I've seen before include "Twelve o'clock in the day" , "Twelve o'clock, midday" , "The middle of the day" , "12 o'clock" , "Twelve during daylight" .)