Article on feet is a crime (5)
I believe the answer is:
theft
'crime' is the definition.
(theft is a kind of crime)
'article on feet' is the wordplay.
'article' becomes 'the' (the definite article in English).
'on' says to put letters next to each other (in a down clue, letters appear on others).
'feet' becomes 'ft' (I've seen this in other clues).
'the'+'ft'='THEFT'
'is a' acts as a link.
(Other definitions for theft that I've seen before include "Burglary" , "crime incident" , "Dishonest appropriation" , "Unlawful taking" , "heavy crime" .)