der Zoll
customs duty
A state fee or tax that is levied on goods when they are brought across a national border.
Für die Einfuhr des Autos musste er einen hohen Zoll bezahlen.
He had to pay a high customs duty for importing the car.

customs duty / customs / inch
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customs duty
A state fee or tax that is levied on goods when they are brought across a national border.
Für die Einfuhr des Autos musste er einen hohen Zoll bezahlen.
He had to pay a high customs duty for importing the car.

The three meanings of 'Zoll' are clearly separated by context. If it is about money or fees, the tax is meant. If it is about an authority or border control, the institution is meant. If a number comes before it and the topic is size, the unit of measurement is meant.
Wie hoch ist der Zoll für diese Waren?
How high is the customs duty for these goods?
When the authority is meant, 'Zoll' is often treated like a place and used with prepositions such as 'am Zoll' (at customs / at the checkpoint) or 'beim Zoll' (at customs / with the customs authority).
Am Zoll mussten wir unsere Koffer öffnen.
At customs, we had to open our suitcases.
As a unit of length, 'Zoll' is almost always used together with a number. It is mainly used for the diagonal size of screens (TVs, monitors) or for diameters (e.g., pipes).
Das Tablet hat ein 10-Zoll-Display.
The tablet has a 10-inch display.
centimeter
'der Zentimeter' and 'der Zoll' can both indicate lengths. A centimeter belongs to the metric system and is used very often in everyday life in Germany for small lengths. An inch is a different unit of length and equals 2.54 centimeters. You see 'Zoll' especially for screen sizes or certain technical measurements. Learners may confuse the words because both measure things, but the numbers are not the same. The important point is: 10 centimeters are not 10 inches.

Für den neuen Schreibtisch sucht er einen Bildschirm mit 27 Zoll.
For his new desk, he is looking for a 27-inch monitor.
Die Verkäuferin misst den Stoff auf 80 Zentimeter ab.
The saleswoman measures out 80 centimeters of fabric.