Port that's cheap is flat — oddly left out (5)

I believe the answer is:

haifa

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'port' is the definition.
(I know that Haifa is a port)

I cannot understand how the remainder of the clue works.

(Other definitions for haifa that I've seen before include "Israel's main port" , "Port of N. Israel" , "Middle East city" , "Israeli city" , "Major port in northwestern Israel" .)

I've seen this clue in The Times.

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