Verjuice n. : The sour juice of crab apples, of green or unripe grapes, apples, etc.; also, an acid liquor made from such juice.

Verjuice n. : Tartness; sourness, as of disposition.

Example:
were can i get Verjuice?

Taxonomy
verjuice, verjus, juice, wine, free encyclopedia, cooks, apple juice, Recipes, widely used, acidic, the Middle Ages, ingredient, vinegar, lemon juice, South Australian, Medieval Kitchen, Italy, green grapes.

Defination from the web:
Verjuice (from Middle French vertjus "green juice") is a very acidic juice made by pressing unripe grapes. ... The South Australian cook Maggie Beer has popularised the use of verjuice in her cooking, and it is being used increasingly in South Australian restaurants. ...