yeast used in pharmacology, for experiments or as medication
- I'd give more detailed explenation if I knew the context
- Here is the dictionary definition (M. Webster's Collegiate Dict.):
PLACEBO 1) : a medication prescribed more for the mental relief of the patient than for its actual effect on a disorder
(2) : an inert or innocuous substance used esp. in controlled experiments testing the efficacy of another substance (as a drug)