Hawaiian garland, but the French have one (3)
I believe the answer is:
lei
'hawaiian garland' is the definition.
(I've seen this before)
'the french have one' is the wordplay.
'the french' becomes 'le' ('the' in French).
'have' is a charade indicator (letters next to each other).
'one' becomes 'i' (Roman numeral).
'le'+'i'='LEI'
'but' acts as a link.
(Other definitions for lei that I've seen before include "Flower garland of Hawaii" , "Bloomers on line" , "Flower arrangements" , "Honolulu chain of flowers" , "Garland of flowers in Hawaii" .)