Trendy dresser seeing first article under way (11)

I believe the answer is:

fashionista

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'trendy dresser' is the definition.
(fashionable person)

'seeing first article under way' is the wordplay.
'seeing' becomes 'ist' (I can't explain this - if you can you should give a lot more credence to this answer).
'first article' becomes 'a' (ist letter of 'article').
'under' means one lot of letters go next to another.
'way' becomes 'fashion' (synonyms).
'ist'+'a'='ista'
'ista' put after 'fashion' is 'FASHIONISTA'.

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I've seen this clue in The Telegraph.

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