The Hittites used the seeds of a particular plant, now known to have been called marashanha, in a ritual for cursing a conquered city to ensure its desolation. Other parts of the same plant provided food and medicine. We have combined textual, botanical, linguistic and herbalist evidence to propose that marashanha denoted at least one species of fennel. This plant readily colonises deserted habitation sites and possesses properties in common with marashanha. We further propose that the Anatolian word ‘marashanha’ has a common origin with the Greek word for fennel, ‘marath(r)o-’, and that the impact of folk etymology on the latter reflects the use of fennel as a female contraceptive. Fennel's ability to inhibit conception accords with the barrenness which the Hittite ritual sought to impose upon a conquered city.