Pronunciation: (plu-sē'bō for 1; plä-chā'bō for 2), [key]
—pl. -bos, -boes.
1. Med., Pharm.
a. a substance having no pharmacological effect but given merely to satisfy a patient who supposes it to be a medicine.
b. a substance having no pharmacological effect but administered as a control in testing experimentally or clinically the efficacy of a biologically active preparation.
2. Rom. Cath. Ch.the vespers of the office for the dead: so called from the initial word of the first antiphon, taken from Psalm 114:9 of the Vulgate.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.