Left German single (4)
I believe the answer is:
gone
'left' is the definition.
(go can mean to leave)
'german single' is the wordplay.
'german' becomes 'g' (abbreviation).
'single' becomes 'one' (a single thing - only one).
'g'+'one'='GONE'
(Other definitions for gone that I've seen before include "Departed or no longer available" , "Well in the past" , "... saga of 2's civil war" , "Away, departed" , "Departed or dead" .)