seven

   Powerful and lucky, like other odd *numbers, and also because it corresponds to the seven *days of the week, themselves derived from the moon's phases in its 28-day cycle. In folk belief, it is linked to the idea of cycles of growth: at 7, a child supposedly reaches 'the age of reason'; at 14, puberty; at 21 (formerly), legal adulthood. In astrology and old medical theory, every seventh year of one's life was a time of crisis, the most dangerous being one's sixty-third year (9 x 7), the 'grand climacteric'. There is still a fairly common idea that in the course of seven years every cell in one's body is renewed.

   In folk magic, seven is less often mentioned than *three or *nine, but does occur; it may be said, for example, that running seven times round a particular *grave will raise a *ghost. A * seventh son (or daughter) was widely credited with healing power.