Still an apartment (4)

I believe the answer is:

flat

I believe this is a double definition.

'still' is the first definition.
(thesaurus)

'an apartment' is the second definition.
(synonyms)

(Other definitions for flat that I've seen before include "Level; pad" , "Not hilly" , "Prostrate" , "Pressing implement" , "lacking in taste" .)

I've seen this clue in The Times.

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