Same sort of stitching (4)
I believe the answer is:
seam
'stitching' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'same sort' is the wordplay.
'sort' indicates anagramming the letters.
'same' is an anagram of 'SEAM'.
'of' is the link.
Can you help me to learn more?
(Other definitions for seam that I've seen before include "Stitched joint" , "Line of sewing - stratum of coal" , "Fabric joint" , "Fabric join" , "Line of join" .)