Edifice with strong beams (10)

I believe the answer is:

lighthouse

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'edifice' is the definition.
(I know that lighthouse is a type of edifice)

I don't understand the remainder of the clue.

Can you help me to learn more?

(Other definitions for lighthouse that I've seen before include "Tall structure emitting flashes to guide ships" , "Beamer" , "it sends a warning" , "tower" , "Warning feature for shipping" .)

I've seen this clue in The Globe and Mail.

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