It has to be weighed before leaving (6)

I believe the answer is:

anchor

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'it has to be weighed before leaving' is the definition.
The definition suggests a singular noun which matches the answer.

This is all the clue.

Can you help me to learn more?

(Other definitions for anchor that I've seen before include "Ship's fluke" , "Device to keep ship in place" , "Brake for a boat" , "Device used to prevent vessel from drifting" , "Weigh down" .)

I've seen this clue in The Irish Independent.

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