Crossword Genius

A small puff - blue (3)

Ross

I believe the answer is:

sad

'blue' is the definition.
(similar in meaning)

'a small puff' is the wordplay.
'a small' becomes 's' (abbreviation - e.g. clothes size).
'puff' becomes 'ad' (short for advert - a puff piece is an advertisemen).
's'+'ad'='SAD'

(Other definitions for sad that I've seen before include "Miserable" , "Mournful - sorry" , "Mournful and depressed" , "Regrettable" , "Gloomy" .)

I've seen this clue in the Evening Standard.
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