Definition of deleterious in US English:

deleterious

adjective

formal
  • Causing harm or damage.

    ‘divorce is assumed to have deleterious effects on children’
    • ‘The resulting instability often has deleterious effects on the children of the relationship.’
    • ‘In fact, the war itself would have had a deleterious effect on tourism, one would have thought.’
    • ‘A healthy person can consume a large quantity of water without any deleterious effect.’
    • ‘Special tax treatment for health benefits has several deleterious effects.’
    • ‘This type of genetic shuffling may have unpredictable, often deleterious effects.’
    • ‘Moreover, scientific studies on choking reveal no deleterious after effects.’
    • ‘And finally, it examines the deleterious effect that this might have on the performer and the people around them.’
    • ‘The virus causes about 1 million deaths a year due to its deleterious effects on the liver.’
    • ‘The world situation has had deleterious effects on a couple of international film festivals this week.’
    • ‘In general, these drugs have no deleterious effects on training or competition.’
    • ‘So what can be done to wind back the deleterious effects of confidentiality agreements on public safety?’
    • ‘I think, to that degree, it may have had a deleterious effect upon the medium since then.’
    • ‘It is currently unknown whether the deleterious effects of fats are limited to specific fatty acids.’
    • ‘Any move is likely to have a deleterious effect on their health and will certainly adversely affect the quality of their life.’
    • ‘Some deleterious effects ascribed to lead may include contributions from other metals.’
    • ‘Nor do they show evidence of any long-term deleterious effect in children attending day-care from an early age.’
    • ‘As for carbon dioxide emission - if this does have a deleterious effect, how should we deal with the problem?’
    • ‘Actions taken because of the fear of this older future are already having deleterious effects for lots of older people.’
    • ‘We should vigorously oppose such a show, which can only have a deleterious effect on the moral and spiritual climate of our city.’
    • ‘The deleterious effect is that there can be no public scrutiny and comment on the conduct of the police investigation.’
    harmful, damaging, detrimental, injurious, inimical, hurtful, bad, adverse, disadvantageous, unfavourable, unfortunate, undesirable
    View synonyms

Origin

Mid 17th century: via medieval Latin from Greek dēlētērios ‘noxious’ + -ous.

Pronunciation

deleterious

/ˌdeləˈtirēəs//ˌdɛləˈtɪriəs/