Definition of nocebo in English:


nounPlural nocebos

  • A detrimental effect on health produced by psychological or psychosomatic factors such as negative expectations of treatment or prognosis.

    • ‘Section Four, ‘Essays and Commentaries,’ examines aromatherapy and essential oils and homeopathy, the placebo effect, and herbs as a token and nocebos.’
    • ‘It is also worth noting that the placebo has a negative counterpart - called a nocebo.’
    • ‘Because of ethical concerns, nocebos are not commonly used in medical practice or research.’


1960s: from Latin, literally ‘I shall cause harm’, from nocere ‘to harm’, on the pattern of placebo.