Aniseed is the seed of the anise plant. Cooks and sweet-makers use it, and so do makers of some strong drinks that smell of liquorice. In Britain this is the usual word for those seeds; in American English you more often hear “anise seed” or just “anise”. The seeds are small and dry, and a little is enough. Though actually, shop jars labelled aniseed are sometimes mixed with fennel or star anise, which smell close but are not the same seed.