Screw Top to a Petrol Tank

This page is the CodyCross answer for the clue below from Cruise Ship, Group 660, Puzzle 2 (Mediterranean).

Question is: Screw Top to a Petrol Tank

and the answer is: FILLERCAP

Word Meaning:

FILLER CAP — The cap that closes the opening of a tank, e.g. the fuel tank of a car, through which the tank can be filled.

Definitions from Wiktionary.