phone treenoun.
A telephone campaign in which a group of people are contacted about an issue, and each person is asked to contact other people about that issue, and so on.
Example Citation:
"Meanwhile, the Ontario Coalition for Health Care had heard the same news at 8 a.m. and put their election strategy into action. By 10:30 a.m., their school bus had been chartered and their 'phone tree' had mobilized 50 instant demonstrators to dog Harris' big day."
—Michele Mandel, "Reality Intrudes On Mike's Big Day," The Toronto Sun, May 6, 1999
