Article written about one following crook (5)
I believe the answer is:
thief
'crook' is the definition.
(I know that thief is a type of crook)
'article written about one following' is the wordplay.
'article' becomes 'the' (the definite article in English).
'written about' indicates putting letters inside.
'one' becomes 'i' (Roman numeral).
'following' becomes 'f.' (used when citing page numbers etc).
'the' going around 'i' is 'thie'.
'thie'+'f'='THIEF'
(Other definitions for thief that I've seen before include "Aus. or Scots city" , "Afternoon break" , "nicker?" , "Pilferer" , "A robber or pickpocket" .)