No opening in battle for torpedo, say (3)

I believe the answer is:

ray

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'for torpedo say' is the definition.
(torpedo is a kind of ray)

I don't understand the rest of the clue.

(Other definitions for ray that I've seen before include "Pencil of light" , "Gleam" , "bit of sunshine" , "A little light" , "Broad flat fish; beam" .)

I've seen this clue in The Independent.

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