Everyone’s short on cash by now (7)
I believe the answer is:
already
'by now' is the definition.
(I've seen this in another clue)
'everyone's short on cash' is the wordplay.
'everyone' becomes 'all' (all people).
'short' means to remove the last letter.
'on' means one lot of letters go next to another.
'cash' becomes 'ready' (ready can informally refer to cash).
'all' with its final letter taken away is 'al'.
'al'+'ready'='ALREADY'
(Other definitions for already that I've seen before include "Previously" , "thus far" , "By the time in question" , "Indication of impatience (US)" , "earlier than might have been expected" .)