An Indian, oddly, appearing in Verdi opera (4)
I believe the answer is:
aida
'verdi opera' is the definition.
(I've seen this before)
'an indian oddly' is the wordplay.
'oddly' means one should take alternating letters.
'an'+'indian'='anindian'
The alternating letters of 'anindian' are 'AIDA'.
'appearing in' acts as a link.
(Other definitions for aida that I've seen before include "Verdi's slave girl" , "title role" , "work of grand proportions" , "Verdi's opera set in ancient Egypt" , "eponymous heroine" .)