Placebo (noun)

1. A substance or treatment with no therapeutic effect, used as a control in testing new drugs.
2. An inactive treatment or medication used as a control in a scientific study.

Origin:

From latin placere, meaning "to please".

Examples:

1. The patients who received the placebo experienced no change in their condition.
2. The placebo group in the study did not see any improvement in their symptoms.
3. The placebo effect can cause people to feel better even though the treatment is not effective.
4. Some people in the study were given a sugar pill as a placebo.
5. The researchers found that the new drug was more effective than the placebo.