filler cap

British  

noun

1. a device sealing the filling pipe to the petrol tank in a motor vehicle

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Example Sentences

There's an easy access filler cap where the water can be changed every three to five days.

From Salon

WHY: The filler cap at the top of the unit can crack and allow steam to escape, posing a risk of burns to the user.

From Seattle Times

Small details complete the look, like the motorcycle-inspired petrol filler cap that hides the EV plug and the leather straps that hold the headlight covers in place.

From The Verge

He located the filler cap under the front bunk cushions when he took all the cushions out and put them topside to dry in the sun.

From Literature

Porcelain is also used on the center wheel badges, the fuel filler cap, and the oil filler cap.

From Forbes