0 an area in a field of crops where the crops have been made flat in a regular pattern, often a circle or series of circles, which people sometimes believe has been done by aliens (= creatures from a different planet):
Fall often brings sightings of mysterious crop circles in Ohio, and this season the Miami Valley has one of its own.
The famous crop circles of England were exposed as the work of human pranksters, not space aliens.
Several scientific papers suggest other possible explanations for the crop circle phenomenon than aliens or pranksters.
