Nominally, it could be misleading (5)
I believe the answer is:
alias
This could be a double definition.
'nominally' is the first definition.
Both the answer and definition are adverbs. Perhaps you can see a link between them that I can't see?
'it could be misleading' is the second definition.
The definition suggests a singular noun which matches the answer.
Can you help me to learn more?
(Other definitions for alias that I've seen before include "stage name, perhaps" , "Cabbage salad" , "aka" , "Otherwise - an assumed name" , "Pseudonym" .)