Crossword Genius

Light first-class railway (4)

Ross

I believe the answer is:

airy

'light' is the definition.
(synonyms)

'first-class railway' is the wordplay.
'first class' becomes 'ai' (A1 - top quality).
'railway' becomes 'ry' (abbreviation for railway).
'ai'+'ry'='AIRY'

(Other definitions for airy that I've seen before include "Flippant" , "Lacking substance" , "affecting nonchalance" , "Breezy" , "Spacious - aerial" .)

I've seen this clue in the Sydney Morning Herald.
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