Friends disappear in a fog, finally invisible (6)

I believe the answer is:

amigos

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'friends' is the definition.
(I have seen 'Hispanic friends ' mean 'amigos' so perhaps 'friends' could also mean 'amigos')

I don't understand the remainder of the clue.

Can you help me to learn more?

(Other definitions for amigos that I've seen before include "comrades in Spain" , "chums" , "Mexican pals" , "Hispanic friends" , "Friends (Spanish)" .)

I've seen this clue in The Telegraph.

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