The term “herb” is often used to describe any plant with leaves, seeds, or flowers used for flavoring, food, medicine, or fragrance . Herbs can be distinguished from spices, which are usually dried and come from other parts of the plant, such as bark, roots, or fruits. Definition of herb noun in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more. This is a list of herbs and spices, ordered alphabetically by common name. (See also spice and herb ; spice trade.) In botany, a herb or herbaceous plant (pronounced with or without the h) technically is a seed -bearing plant (most specifically a flowering plant) that does not produce a woody stem with persistent tissue but generally dies down to the ground level each year.