Ancient Phoenician port in southern Lebanon known for the production of a rare sort of purple dye (4)
I believe the answer is:
tyre
(Other definitions for tyre that I've seen before include "A spare one round the middle is fat" , "A spare one may be fat around the middle" , "Rubber surround on a wheel" , "Wheel cover, may be tubeless" , "Rubber part of wheel" .)