Nurse with dead leg (one supporting double bass) (3,3)

'one supporting double bass' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.

'nurse with dead leg' is the wordplay.
I cannot really understand how this works, but
'nurse' could be 'en' (abbreviation for enrolled nurse) and 'en' is present in the answer.
'dead' could be 'd' (abbreviation in government records) and 'd' is found in the answer.
'leg' could be 'pin' (pin is a kind of leg) and 'pin' is found in the answer.
This accounts for all the letters.
This explanation may well be incorrect...

Can you help me to learn more?