Odd dearth of sewing material (6)

I believe the answer is:

thread

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'dearth of sewing material' is the definition.
(I've seen this before)

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for thread that I've seen before include "The rib going around a screw" , "Hatred (anag)" , "Messages on a theme" , "Thin strand" , "Fine cord of twisted fibers" .)

I've seen this clue in The Mirror.

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