Article secured by odd bits of their rope (6)
I believe the answer is:
tether
'rope' is the definition.
(thesaurus)
'article secured by odd bits of their' is the wordplay.
'article' becomes 'the' (the 'definite article' part of speech).
'secured by' is an insertion indicator (I've seen this in other clues).
'odd bits of' means one should take alternating letters.
The alternating letters of 'their' are 'ter'.
'the' going within 'ter' is 'TETHER'.
(Other definitions for tether that I've seen before include "Rope for tying animals" , "Rope for hobbling animal" , "Restrain within limits" , "restrain boxers, say" , "moor" .)