Picked up large jar (5)
I believe the answer is:
grate
'jar' is the definition.
(make unpleasant sound)
'picked up large' is the wordplay.
'picked up' shows a homophone (sound like).
'large' becomes 'great' (similar in meaning).
'great' sounds like 'GRATE'.
(Other definitions for grate that I've seen before include "Grind (teeth)" , "Fireplace recess; rasp" , "Great (anag.)" , "Jar; fireplace" , "Barred framework" .)