Fall, for every one’s hard (6)
I believe the answer is:
perish
'fall' is the definition.
(I've seen this before)
'every one's hard' is the wordplay.
'every' becomes 'per' (I've seen this in other clues).
'one's' becomes 'is' (roman numeral).
'hard' becomes 'h' (abbreviation used in pencil classifications).
'per'+'is'+'h'='PERISH'
'for' is the link.
(Other definitions for perish that I've seen before include "Die; decay" , "Pass away" , "Waste away" , "Lose one's life" , "Suffer complete ruin or destruction" .)