The hospital floor, perhaps (5)

I believe the answer is:

level

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'floor perhaps' is the definition.
(floor is a kind of level)

I don't understand the rest of the clue.

(Other definitions for level that I've seen before include "Staying at same height" , "Standard" , "Palindromic storey" , "Flatten" , "Flat, even" .)

I've seen this clue in the Evening Standard.

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