Author Philip in sleeping car (7)

I believe the answer is:

pullman

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'sleeping car' is the definition.
(I've seen this in another clue)

I don't understand the remainder of the clue.

(Other definitions for pullman that I've seen before include "Luxury railway carriage" , "Philip --, novelist" , "Luxurious style of railway carriage" , "luxury car" .)

I've seen this clue in The Sun.

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