The French, in the modern era, are first (4)
I believe the answer is:
lead
'are first' is the definition.
(lead can mean leading or primary)
'the french in the modern era' is the wordplay.
I cannot quite see how this works, but
'modern' could be 'ad' (I've seen this in other clues) and 'ad' is found within the answer.
'the french' could be 'le' ('the' in French) and 'le' is present in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for lead that I've seen before include "Go ahead; element" , "first name in lights?" , "Heavy malleable metallic element" , "Go first" , "Church windows include this" .)