Sews in zigzag style? (5)

I believe the answer is:

tacks

I'm a little stuck... Click here to teach me more about this clue!

'sews' is the definition.
(I know this)

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

(Other definitions for tacks that I've seen before include "They secure" , "Fixes" , "Short nails" , "Changes course" , "Drawing pins" .)

I've seen this clue in the Evening Standard.

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