Unhealthy looking bird, having lost a wife (6)

I believe the answer is:

sallow

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'unhealthy looking' is the definition.
(I've seen this before)

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

(Other definitions for sallow that I've seen before include "Unhealthily pale; a willow" , "Pale-looking - tree ..." , "(Of complexion) rather yellowish" , "Unhealthy looking" , "(Of complexion) pale and unhealthy" .)

I've seen this clue in The Guardian.

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