A strange notion for a Venetian trader (7)
I believe the answer is:
antonio
'venetian trader' is the definition.
The definition suggests a singular noun which matches the answer.
'a strange notion for a' is the wordplay.
'a strange' indicates an anagram.
'for' is a charade indicator (letters next to each other) (I've seen this in other clues).
'notion' with letters rearranged gives 'ntonio'.
'ntonio' after 'a' is 'ANTONIO'.
Can you help me to learn more?
(Other definitions for antonio that I've seen before include "merchant threatened by weight loss" , "Name of the Merchant of Venice who borrowed money" , "Portia's client" , "One contracted for a pound" , "A notion about The Merchant of Venice" .)