Traveller of sound mind in Glasgow? (5)

I believe the answer is:

nomad

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'traveller' is the definition.
(I know that Nomad is a type of bird of passage)

I can't explain the rest of the clue.

(Other definitions for nomad that I've seen before include "Migrant" , "is one unsettled?" , "Itinerant" , "One travels from place to place with no permanent home" , "One keeps moving" .)

I've seen this clue in The Sun, The Times and The Telegraph.

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