Detest swearword in French article (6)
I believe the answer is:
loathe
'detest' is the definition.
(loathing is a kind of detesting)
'swearword in french article' is the wordplay.
'swearword' becomes 'oath' (oath can mean a swearword).
'in' is an insertion indicator.
'french article' becomes 'le' (definite article in French).
'oath' put into 'le' is 'LOATHE'.
(Other definitions for loathe that I've seen before include "Dislike intensely" , "Hate (someone)" , "Feel strong disgust for" , "Greatly hate" , "cannot stand" .)