Spat hard bit of sausage out (4)

I believe the answer is:

tiff

'spat' is the definition.
(I know that spat can be written as tiff)

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

(Other definitions for tiff that I've seen before include "Lovers' row" , "Petty argument" , "Slight argument" , "Mild quarrel" , "Minor argument" .)

I've seen this clue in The Guardian.

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