juice noun 1 the liquid or sap from fruit or vegetables. 2 (usu juices) the body's natural fluids digestive juices . 3 vitality; piquancy. 4 slang power or fuel, especially electricity or petrol step on the juice . 5 US slang alcoholic drink. verb (juiced , juicing ) to squeeze juice from (a fruit, etc). [13c: from French jus ] juiceless adjective .