Occupant makes chief exec powerless (8)

I believe the answer is:

resident

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'occupant' is the definition.
(synonyms)

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

(Other definitions for resident that I've seen before include "One living in the place referred to" , "always in memory" , "Person living in" , "Liver" , "Lodger" .)

I've seen this clue in The Sun.

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