TV detective seen on winter mornings (5)

I believe the answer is:

frost

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'winter mornings' is the definition.
'frost' can be an answer for 'winter' (thesaurus). I'm not certain of the 'mornings' bit.

I can't explain the remainder of the clue.

Can you help me to learn more?

(Other definitions for frost that I've seen before include "Icy condensation" , "Hoar" , "Rime" , "Frozen dew" , "Robert ---, US poet" .)

I've seen this clue in The Daily Express.

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