Crossword Genius

Henry, entering American joints, wanders vacantly (7)

Ross

I believe the answer is:

mithers

I'm a little stuck... Click here to teach me more about this clue!

'joints wanders vacantly' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.

'henry entering american' is the wordplay.
'henry' becomes 'H' (symbol for the unit of electrical inductance).
'entering' means one lot of letters goes inside another.
'american' becomes 'miters' (I can't justify this - if you can you should believe this answer much more).
'h' placed into 'miters' is 'MITHERS'.

Can you help me to learn more?

I've seen this clue in The Independent.
Want a hint initially instead of a full solution? Install my app