Crossword Genius

Surreptitiously altering a skyline (8)

Ross

I believe the answer is:

sneakily

'surreptitiously' is the definition.
('sneakily' can be a synonym of 'surreptitiously')

'altering a skyline' is the wordplay.
'altering' indicates an anagram.
'a'+'skyline'='askyline'
'askyline' anagrammed gives 'SNEAKILY'.

I've seen this clue in The Independent.
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