Footwear which doesn't help one keep one's feet? (7)

I believe the answer is:

slipper

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'footwear' is the definition.
(I know that slipper is a type of footwear)

I don't understand the remainder of the clue.

(Other definitions for slipper that I've seen before include "pump" , "runner" , "Footwear item" , "Ripples (anag.)" , "Nearby; pub" .)

I've seen this clue in The Irish Independent.

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