Scotch form of transport (6)

I believe the answer is:

whisky

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'scotch' is the definition.
(I've seen this before)

I cannot understand how the rest of the clue works.

(Other definitions for whisky that I've seen before include "Scottish spirit" , "reportedly available for Thin Lizzy gig?" , "W in radio alphabet" , "Alcoholic drink" , "Grain alcohol" .)

I've seen this clue in The Irish Independent.

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