placebo
/pləˈsiːbəʊ/noun
(pl. -os)
1- a pill, medicine, or procedure prescribed more for the psychological benefit to the patient of being given a prescription than for any physiological effect（给病人提供心理作用的）安慰剂。
1.1
- a substance that has no therapeutic effect, used as a control in testing new drugs（用于检测新药的）无效对照剂。
1.2
- figurative a measure designed merely to calm or please someone〈喻〉安慰措施; 宽慰措施。
词源
late 18th cent.: from Latin， literally 'I shall be acceptable or pleasing'， from placere 'to please'.