Semantics of the placebo
With increased interest in the placebo effect and clinical methodology, definitions of the placebo have proliferated. But there is little agreement among lexicographers, historians, clinicians, and researchers about how to define this word. Derivations of the wordplacebo from the Hebrew and Latin and its use in the Bible and literature were reviewed. Historical inaccuracies in classical references to the placebo's origin, history, and development were corrected. An explanation was given for the introduction of the word in 1785, and for the changes in definition that have appeared since that time. Definitions of the placebo and placebo effect, based on historic considerations and heuristic principles, were then proposed.