A low American (4)
I believe the answer is:
heel
This could be a double definition.
'a low' is the first definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe you can see a link between them that I don't see?
'american' is the second definition.
The answer and definition can be both people as well as being singular nouns.
Maybe they are linked in a way I don't understand?
Can you help me to learn more?
(Other definitions for heel that I've seen before include "horrible person" , "Bounder; part of foot" , "Back of 15 across" , "Scoundrel - list - shoe part" , "Not the sole - scoundrel" .)