1. to cause (eg. a party) to split into two sub-parties, due to mutual incompatibility between the guests.
2. (of a party) to split into two sub-parties
Named after John Ewing, legend in several fields, whose flatwarming party was the first to display this trait, after half of the guests decamped to the kitchen on the arrival of several of his classmates from university.
"The party really ewinged after those twunts arrived."
"Oh dear, we've ewinged this party."