Coriander is used as "a stimulant, aromatic and carminative. The powdered fruit, fluid extract and oil are chiefly used medicinally as flavoring to disguise the taste of active purgatives and correct their griping tendencies." -- Botanical.com

*** So it's used to disguise the terrible tobacco taste in cigarettes??? ***

From CulinaryCafe.com:

General Description
Coriander is the seed of Coriandrum sativum, a plant in the parsley family. The seed is globular and almost round, brown to yellow red, and 1/5 inch in diameter with alternating straight and wavy ridges.

Geographical Sources
Coriander comes from Morocco and Romania.

Traditional Ethnic Uses
Coriander is used in Indian curries, gin, American cigarettes, and sausages.

Taste and Aroma
Coriander has a mild, distinctive taste similar to a blend of lemon and sage.