Verjus

(grape variety) The white grape comes from Italy, Synonyms include Agras, Agryas, Agyras, Aigrun, Aygras, Ciprinao, Gregory, Gros Verjus, Prunesta, St Marie Blanche, White Verjus and White Verjus. About the descent or possible connection to the red variety Prunesta nothing is known. The variety was crossing partner in the new breed Rose Musc...
Found on https://glossary.wein-plus.eu/verjus-grape-variety

verjus

juice from unripe grapes; once used in sauces instead of vinegar
Found on http://www.slowtrav.com/france/restaurants/glossary.htm

Verjus

Sour juice made from under ripe grapes, it's popular as a substitute for vinegar and has a mild grapelike flavor..
Found on http://www.encyclo.co.uk/local/21216

Verjus

the juice of unripe grapes, used to make a condiments used much like vinegar in sauces.
Found on http://www.patriciawells.com/glossary/
No exact match found