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Medical Term:


Pronunciation: plă-sē′bō


  1. An inert substance given as a medicine for its suggestive effect.
  2. An inert compound identical in appearance to material being tested in experimental research, which may or may not be known to the physician or patient, administered to distinguish between drug action and suggestive effect of the material under study.

Synonym(s): active placebo

[L. I will please, future of placeo]