Lowest part of car port (4)
I believe the answer is:
tyre
This might be a double definition.
'lowest part of car' is the first definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'port' is the second definition.
(I know that Tyre is a port)
Can you help me to learn more?
(Other definitions for tyre that I've seen before include "Band on wheel" , "Old Phoenician port" , "Wheel-hoop" , "Rubber part of wheel" , "Pumped-up" .)