His progress is pedestrian (5)

I believe the answer is:

hiker

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'pedestrian' is the definition.
(hiker is a kind of pedestrian)

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

(Other definitions for hiker that I've seen before include "Trekker" , "Person on walkabout" , "Backpacker" , "Foot traveller" , "Country walker" .)

I've seen this clue in the Evening Standard.

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