pla‧ce‧bo /pləˈsiːbəʊ $ -boʊ/ noun (plural placebos) [countable]
[Date: 1700-1800; Language: Latin; Origin: 'I shall please', from placere; ⇒ please²]

1. a harmless substance given to a sick person instead of medicine, without telling them it is not real. Placebos are often used in tests in which some people take real medicine and others take a placebo, so that doctors can compare the results to see if the real medicine works properly.

2. placebo effect when someone feels better after taking a placebo, even though it has not had any effect on their body

[TahlilGaran] Dictionary of Contemporary English ▲