Concealed the hideous part (3)

I believe the answer is:

hid

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'concealed' is the definition.
('hide' can be a synonym of 'conceal')

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

Can you help me to learn more?

(Other definitions for hid that I've seen before include "Concealed from sight" , "wanted to be sought?" , "Remained out of sight" , "Concealed, kept secret" , "Kept out of sight" .)

I've seen this clue in the Evening Standard.

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