Confuse foreign refusal with positive (7)
I believe the answer is:
nonplus
'confuse' is the definition.
(I know this)
'foreign refusal with positive' is the wordplay.
'foreign refusal' becomes 'non' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'with' says to put letters next to each other.
'positive' becomes 'plus' (similar in meaning).
'non'+'plus'='NONPLUS'
Can you help me to learn more?
(Other definitions for nonplus that I've seen before include "Surprise and confuse" , "State of confusion" , "disadvantageous or neutral, presumably" , "Utterly confuse" , "Flummox" .)