Definition of "placebo"

The acid test, I thought, was whether homeopathic remedies behave differently from placebos when submitted to clinical trials.

2010 February 22, Edzard Ernst, The Guardian

The trials overall showed some but limited effectiveness, and in one of the largest and longest trials, the placebo performed better in treating spasticity, pain and bladder dysfunction, Dr. Bowling wrote.

2021 March 8, Jane E. Brody, “Medical Marijuana Is Not Regulated as Most Medicines Are”, in The New York Times‎

There the placebo, the office for the dead, was sung, and a vigil kept throughout the night.

2011, Thomas Penn, Winter King, Penguin, published 2012, page 349