Hang key at corner (6)
I believe the answer is:
dangle
'hang' is the definition.
(dangling is a kind of hanging)
'key at corner' is the wordplay.
'key' becomes 'd' (musical key).
'at' is a charade indicator (letters next to each other).
'corner' becomes 'angle' (eg a corner of a shape).
'd'+'angle'='DANGLE'
(Other definitions for dangle that I've seen before include "wave" , "Hang provocatively" , "Hang loosely or swing" , "Temptingly offer" , "Suspend in front of Glenda" .)