Fairy Circle, or Fairy Ring

Fairy Circle , or Fairy Ring an appearance pretty frequently seen in the fields, &c. being a kind of round, supposed by the vulgar to be traced by fairies in their dances. There are 2 sorts of these rings or circles; one of them is about 7 or 8 yards in diameter, being a round bare path about a foot in breadth, having green grass in the middle; the other is of different sizes, being encompassed with a circumference of grass, much fresher and greener than that in the middle.
The philosophers supposed these rings to be made by lightening, and this opinion seems to be confirmed, in that they are most frequently found after storms, and the colour and brittleness of the grassy roots is a further confirmation.
The second kind of circle they suppose to arise originally from the first, in that the grass that had been burnt up by lightening, usually grows more plentifully afterwards; some authors say, that these fairy rings are formed by ants; these insects being sometimes found travelling in troups therein.

Definition taken from The Universal Etymological English Dictionary, edited by Nathan Bailey (1736)

[previous] * Festiˊno [with Logicians]
Fairy Circle, or Fairy Ring
Festiˊno [with Logicians]
Foot [in Measure]