American editor jumps even when exhausted (4,2)
I believe the answer is:
used up
'exhausted' is the definition.
('use up' can be a synonym of 'exhaust')
'american editor jumps even' is the wordplay.
'american' becomes 'us' (abbreviation for United States).
'editor' becomes 'ed' (abbreviation).
'even' means one should take alternating letters (even-numbered letters are used).
The alternate letters of 'jumps' are 'up'.
'us'+'ed'+'up'='USED-UP'
'when' is the link.
(Other definitions for used up that I've seen before include "Spent" , "Exhausted the supply" , "Consumed, finished" , "Consumed completely" .)