from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. A substance containing no medication and prescribed or given to reinforce a patient's expectation to get well.
  • n. An inactive substance or preparation used as a control in an experiment or test to determine the effectiveness of a medicinal drug.
  • n. Something of no intrinsic remedial value that is used to appease or reassure another.
  • n. Roman Catholic Church The service or office of vespers for the dead.

from the GNU version of the Collaborative International Dictionary of English

  • n. The first antiphon of the vespers for the dead.
  • n. A prescription with no pharmacological activity given to a patient to humor or satisfy the desire for medical treatment.
  • n. a dose of a compound having no pharmacological activity given to a subject in a medical experiment as part of a control experiment in a test of the effectiveness of another, active pharmacological agent.

from The Century Dictionary and Cyclopedia

  • n. In the Roman Catholic Church, the vespers of the office for the dead.
  • n. A medicine adapted rather to pacify than to benefit a patient.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. an innocuous or inert medication; given as a pacifier or to the control group in experiments on the efficacy of a drug
  • n. (Roman Catholic Church) vespers of the office for the dead


Middle English, from Late Latin placēbō, I shall please (the first word of the first antiphon of the service), first person sing. future tense of Latin placēre, to please; see plāk-1 in Indo-European roots.
(American Heritage® Dictionary of the English Language, Fourth Edition)
From Latin placēbō ("I will please"), the first-person singular future active indicative of placeō ("I please"). (Wiktionary)


  •  The term placebo: an inert medication or bogus treatment that is intended to control for expectancy effects.

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  • PHILIPS: Well, I think there is what we call a placebo effect.

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  • And although doctors don't have to use the word "placebo," they should tell patients they are getting an unusual treatment.

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  • If yesterday was about admitting and addressing the illness, today and tomorrow will hopefully be about prescribing a direction for recovery [not a short-term placebo].

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  • In the first instance, the word placebo comes to mind.

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