A much planned publication? (5)

I believe the answer is:

atlas

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'publication?' is the definition.
(atlas is a kind of publication)

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for atlas that I've seen before include "Legendary weightlifter" , "N African mountains - seemaps book" , "Sky-toting Titan" , "used for maps" , "Asian satin" .)

I've seen this clue in the Evening Standard.

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