What held up fleet heading for Troy? (6,3)

I believe the answer is:

aegean sea

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'troy?' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.

I can't explain the remainder of the clue.

Can you help me to learn more?

(Other definitions for aegean sea that I've seen before include "Where the Isles of Greece are" , "Greek island home?" , "Area around Greece" , "Stretch of water between Turkey and Greece" , "Part of Med" .)

I've seen this clue in The Times.

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