coriander, strong-smelling Old World annual herb (Coriandrum sativum) of the family Umbelliferae (parsley family), cultivated for its fruits. Dried coriander seed contains an aromatic oil used as a flavoring, as a medicine, and in liqueurs. The seed itself is used as a spice similarly to that of the related caraway and cumin. Coriander is classified in the division Magnoliophyta, class Magnoliopsida, order Apiales, family Umbelliferae.