English Reference

Word

placebo

Phoneticsplace·bo

US/pɫəˈsiboʊ/

UK/pləsˈiːbəʊ/

Definitions

01medical treatment

B2 · Medicine

n. a pill or treatment that has no medicine in it, used in medical tests to compare with a real drug.

n. an inert substance or procedure administered to a patient or research subject, serving as a control in clinical trials to isolate the effects of an active drug.

“Half of the people in the study received the new medicine, while the others were given a placebo.”

“To ensure the validity of the clinical trial, the researchers conducted a double-blind study where neither the doctors nor the patients knew who received the placebo.”

Technical

Usage

Often used in the phrase 'placebo effect' to describe when a patient feels better simply because they expect to.

Synonyms

dummy pillsugar pillcontrol

Antonyms

active drugmedication

02religious service

C2 · Religion

n. a specific prayer service or song for the dead in the Catholic Church.

n. the vespers in the Office of the Dead, named after the opening word of the first antiphon.

“The monks gathered in the chapel to sing the Placebo for the departed brother.”

“The historical manuscript contains the full musical notation for the Placebo as it was performed in the fourteenth century.”

Archaic · Formal

Usage

Usually capitalized in liturgical contexts.

Synonyms

vespers

Real-World Examples

“A person takes a placebo pill but is warned it may cause side-effects.”
The Guardian · 9 Aug 2026
“These can work differently in a PMDD population than in other patient groups, she explains, often beating a placebo within 24 hours instead of weeks .”
The Guardian · 14 Aug 2026

Etymology

Inherited from Middle English placebo, borrowed from Latin placēbō (“I will please”), the first-person singular future active indicative of placeō (“I please”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Domain

Medicine

This entry

Level
C1 · Advanced
Frequency
Frequent
Updated

Scan code

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English Reference