Turns red; this shows uncertainty (7)

I believe the answer is:

dithers

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'shows uncertainty' is the definition.
Although both the answer and definition are verbs in their -s form, I don't understand how one could define the other.

'turns red this' is the wordplay.
'turns' is an anagram indicator.
'red'+'this'='redthis'
'redthis' with letters rearranged gives 'DITHERS'.

Can you help me to learn more?

(Other definitions for dithers that I've seen before include "Hesitates indecisively" , "Flaps, wavers" .)

I've seen this clue in The Globe and Mail.

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