Tat fringe on jumper during work time (4)
I believe the answer is:
grot
'tat' is the definition.
(I've seen this before)
'fringe on jumper during work time' is the wordplay.
'fringe on jumper' becomes 'r' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'during' indicates putting letters inside.
'work' becomes 'go' (synonyms).
'time' becomes 't' (abbreviation).
'r' placed into 'go' is 'gro'.
'gro'+'t'='GROT'
Can you help me to learn more?
(Other definitions for grot that I've seen before include "Filth" , "Rubbish (slang); picturesque cave (poet.)" , "Refuse" , "tat" .)