Friend mostly ashen-faced (3)

I believe the answer is:

pal

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'friend' is the definition.
(I know that pal is a type of friend)

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

(Other definitions for pal that I've seen before include "Close friend" , "Brother" , "Crony" , "Friend (colloq.)" , "Bud" .)

I've seen this clue in The Sun.

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