Study following unfinished article's yarn (6)
I believe the answer is:
thread
'yarn' is the definition.
(synonyms)
'study following unfinished article's' is the wordplay.
'study' becomes 'read' (synonyms).
'following' means one lot of letters go next to another.
'unfinished' means to remove the last letter.
'article' becomes 'the' (the 'definite article' part of speech).
'the' with its final letter taken away is 'th'.
'read' put after 'th' is 'THREAD'.
(Other definitions for thread that I've seen before include "Thin yarn" , "Filament; connecting link" , "Fine strand" , "Dearth of stitching material" , "The rib going around a screw" .)