A pledge to secretly perform charitable deeds for known or unknown people/groups on a random basis, as in performing random acts of kindness
. It comes from the ancient belief that the small action of a butterfly beating it's wings can cause an earthquake on the other side of the world - small acts can make a huge difference.
His daily butterflying meant another session of guerilla gardening
on the roundabout, whilst her butterflying was to pop a shopping voucher in the post to an address she randomly chose from the telephone directory.