Get excited, foothold centrally defective (4,2)

I believe the answer is:

stir up

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'get excited' is the definition.
(I've seen this before)

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

(Other definitions for stir up that I've seen before include "Foment (trouble)" , "Excite - incite" , "Get excited" , "Cause or provoke trouble" , "Instigate" .)

I've seen this clue in The Times.

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