Almost everyone prepared by the time in question (7)
I believe the answer is:
already
'by the time in question' is the definition.
(I've seen this before)
'almost everyone prepared' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'everyone' becomes 'all' (I've seen this before).
'prepared' becomes 'ready' ('ready' can be similar in meaning to 'prepared'**).
'all' with its last letter taken away is 'al'.
'al'+'ready'='ALREADY'
(Other definitions for already that I've seen before include "Previously" , "Even this soon" , "Indication of impatience (US)" , "By the time in question" , "earlier than might have been expected" .)