Sewer needs a pain in the side (6)
I believe the answer is:
stitch
This clue could be a double definition.
'sewer' is the first definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe there's an association between them I don't understand?
'a pain in the side' is the second definition.
(I've seen this in another clue)
'needs' acts as a link.
Can you help me to learn more?
(Other definitions for stitch that I've seen before include "result of working with needle?" , "Sew - sharp pain in side" , "Sewing loop and sharp pain in the side" , "Sharp spasm of pain in the side" , "Application of needle produces this" .)