Faulty china from Sevres, seconds section
?iss
The definition seems to be faulty or faulty china, but the parsing is so skilfully constructed that I cannot resolve it. TIA if you can!
Yes, rambler, you're right. An intersecting clue had two possible interpretations for the definition - and I took the wrong one (puzzle allowed for one or two letters per cell). Many thanks for your help - it was very puzzling, but now resolved.