or no added sugar, no added sweet flavor; probably sugarless, plain or bitter in taste, but not always. Unsweetened tea is not to everyoneâ€™s taste but unsweetened fruit juices are perfect, as there is no need to add any sweetener to something it is already sweet. Opposites are sweet, saccharine, or syrupy. Food with a vinegary flavor would taste like vinegar. It would be acetous, sour, acid, acidic, tart, astringent, pungent, harsh, acrid; never sweet.