placebo

[ pluh-see-boh for 1; plah-chey-boh for 2 ]
See synonyms for placebo on Thesaurus.com
noun,plural pla·ce·bos, pla·ce·boes.
  1. Medicine/Medical, Pharmacology. : Compare nocebo (def. 1).

    • a substance having no pharmacological effect but given merely to satisfy a patient who supposes it to be a medicine.

    • a substance having no pharmacological effect but administered as a control in testing experimentally or clinically the efficacy of a biologically active preparation.

  2. Roman Catholic Church. the vespers of the office for the dead: so called from the initial word of the first antiphon, taken from Psalm 114:9 of the Vulgate.

Origin of placebo

1
1175–1225 for def. 2; 1775–85 for def. 1; Middle English <Latin placēbō “I shall be pleasing, acceptable”

Words Nearby placebo

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use placebo in a sentence

British Dictionary definitions for placebo

placebo

/ (pləˈsiːbəʊ) /


nounplural -bos or -boes
  1. med an inactive substance or other sham form of therapy administered to a patient usually to compare its effects with those of a real drug or treatment, but sometimes for the psychological benefit to the patient through his believing he is receiving treatment: See also control group, placebo effect

  2. something said or done to please or humour another

  1. RC Church a traditional name for the vespers of the office for the dead

Origin of placebo

1
C13 (in the ecclesiastical sense): from Latin Placebo Domino I shall please the Lord (from the opening of the office for the dead); C19 (in the medical sense)

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for placebo

placebo

[ plə-sē ]


  1. A substance containing no medication and prescribed to reinforce a patient's expectation of getting well or used as a control in a clinical research trial to determine the effectiveness of a potential new drug.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for placebo

placebo

[ (pluh-see-boh) ]


A substance containing no active drug, administered to a patient participating in a medical experiment as a control.

Notes for placebo

Those receiving a placebo often get better, a phenomenon known as the placebo effect.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.