Loose, German and single (6)
I believe the answer is:
undone
'loose' is the definition.
(thesaurus)
'german and single' is the wordplay.
'german and' becomes 'und'.
'single' becomes 'one' (I've seen this before).
'und'+'one'='UNDONE'
(Other definitions for undone that I've seen before include "Brought to ruin or destruction - or not buttoned" , "Reversed" , "Ruined; not tied" , "Annulled; untied" , "Ruined or dismantled" .)