Real Dictionary

fennel
uncountable noun: Fennel is a plant with a crisp rounded base and feathery leaves. It can be eaten as a vegetable or the leaves can be used as a herb.

fennel in American English
a tall herb (Foeniculum vulgare) of the umbel family, with feathery leaves and yellow flowers: its foliage and aromatic seeds are used to flavor foods and medicines
noun: a plant, Foeniculum vulgare, of the parsley family, having feathery leaves and umbels of small, yellow flowers

fennel in British English
noun: a strong-smelling yellow-flowered umbelliferous plant, Foeniculum vulgare, whose seeds and feathery leaves are used to season and flavour food