Irregular discoloration left within clumsy work (6)
I believe the answer is:
blotch
'irregular discoloration' is the definition.
(I've seen this before)
'left within clumsy work' is the wordplay.
I cannot really understand how this works, but
'left' could be 'l' (common abbreviation) and 'l' is present in the answer.
The remaining letters 'botch' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for blotch that I've seen before include "Unsightly patch" , "Irregular patch or mark" , "Large stain" , "Irregularly shaped spot" , "Spot of irregular discoloration" .)