placebo

 
Pronunciation: /pləˈsiːbəʊ/

noun (plural placebos)

  • a medicine or procedure prescribed for the psychological benefit to the patient rather than for any physiological effect.
  • a substance that has no therapeutic effect, used as a control in testing new drugs.
  • a measure designed merely to humour or placate someone: pacified by the placebos of the previous year, they claimed a moral victory

Origin:

late 18th century: from Latin, literally 'I shall be acceptable or pleasing', from placere 'to please'