Avoidance, taboo, something which causes pollution or hindrance, especially to a ceremony. This may include taboo words (see Imi-kotoba) such as kiru, to cut, during a wedding, temporary states of pollution (such as mourning), inauspicious times, dates and years of age (yakudoshi) and dangerous directions for travel. Most popular beliefs about imi including avoidance of dangerous days and inauspicious directions for journeys (kata-imi) which can be evaded by taking an indirect route (kata-tagae) derive from Taoist ideas about the movements of dangerous deities around the points of the compass.
See Onmyo-do.
A Popular Dictionary of Shinto. Brian Bocking.