Reason it out with a foreign girl (8)
I believe the answer is:
senorita
'a foreign girl' is the definition.
The definition and answer can be both people as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
'reason it out' is the wordplay.
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'reason'+'it'='reasonit'
'reasonit' anagrammed gives 'SENORITA'.
'with' acts as a link.
Can you help me to learn more?
(Other definitions for senorita that I've seen before include "Young Spanish woman for notaries" , "Spanish miss" , "Young lady of Spain" , "Treason I commit for young Spanish woman" , "Young Spanish lady" .)