Crossword Genius

Solo flight from German city is completed (4)

Ross

I believe the answer is:

over

'is completed' is the definition.
(synonyms)

I don't understand how the rest of the clue works.

(Other definitions for over that I've seen before include "In the sky?" , "Finished, concluded" , "bridge?" , "superior position" , "remaining" .)

I've seen this clue in The Guardian.
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