Unskilful tailoring of a harem suit (10)
I believe the answer is:
amateurish
'unskilful tailoring of a harem suit' is the definition.
I can't tell whether this defines the answer.
'of a harem suit' is the wordplay.
'of' is an anagram indicator (the answer comes from or 'of' the letters).
'a'+'harem'+'suit'='aharemsuit'
'aharemsuit' is an anagram of 'AMATEURISH'.
Can you help me to learn more?
(Other definitions for amateurish that I've seen before include "done imperfectly" , "using little craft, perhaps" , "Lay" , "Rather 31 across" , "incompetent" .)