In France, one plus seven minus five is not revealed (6)
I believe the answer is:
unseen
'not revealed' is the definition.
The answer and definition are different parts of speech. However, past participle verbs and adjectives occasionally mean the same thing.
'in france one plus seven minus five' is the wordplay.
'in france' becomes 'un' (I've seen this in other clues).
'one plus' says to put letters next to each other.
'minus' is a deletion indicator.
'five' becomes 'V' (Roman numeral).
'seven' with 'v' taken out is 'seen'.
'un'+'seen'='UNSEEN'
'is' is the link.
Can you help me to learn more?
(Other definitions for unseen that I've seen before include "Passage for translation" , "Concealed" , "Invisible or not observed" , "Translation exercise" , "Hidden from view" .)