Word of the Day : October 21, 2015


noun noh-SEE-boh


: a harmless substance that when taken by a patient is associated with harmful effects due to negative expectations or the psychological condition of the patient

Did You Know?

Nocent has been in the English language as a word for harmful since the 15th century. It comes from Latin nocēre, meaning "to harm." Latin nocebo is a close relative that means "I will be harmful" and that contrasts with placebo, meaning "I shall please." People in medicine began using placebo for inert preparations prescribed solely for a patient's mental relief, and not for relieving a disorder, in the late 18th century. As doctors began to observe the effects of placebos, some noticed that the harmless preparations actually sometimes caused detrimental effects on the patient's health. English speakers began using the word nocebo for substances causing such adverse reactions in patients in 1961.


"Medical researchers know about nocebos but are often at a loss how to deal with them. For example, it would be wrong not to tell people about possible side effects of a medicine, yet the more they are educated about side effects, the more side effects they will get." — Alan Christianson, The Huffington Post, 22 Apr. 2015

"For example: Nocebos can induce itch or pain in research subjects who believe that these will be the expected results. Interestingly, placebos and nocebos yield opposite effects upon levels of dopamine and opioid neurotransmitters in specific areas of the brain." — Dennis Rosen, The Pacific Standard, 9 Sept. 2014

Word Family Quiz

Unscramble the letters to create an adjective that is derived from Latin nocēre and can mean "harmless": CUUSNIONO.



More Words of the Day

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!