A vessel in mourning (3)

I believe the answer is:

urn

'a vessel' is the definition.
(urn is a kind of vessel)

'in mourning' is the wordplay.
'in' says the answer is hidden in the clue.
'URN' can be found hidden inside 'mourning'.

(Other definitions for urn that I've seen before include "Holder of the Ashes?" , "Funerary vessel" , "Pot, vase" , "Vase-shaped vessel" , "Large pot for coffee or tea" .)

I've seen this clue in the Evening Standard.

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