Definition of malathion in US English:



  • A synthetic organophosphorus compound that is used as an insecticide and is relatively harmless to plants and other animals.

    • ‘Recommended chemical treatments include such common insecticides as permethrin, malathion, diazinon and sevin.’
    • ‘The alcohol in malathion lotion and the terpenoids may cause stinging.’
    • ‘It is not known whether children are more sensitive to the effects of malathion than adults.’
    • ‘It is not likely that malathion will cause reproductive effects in humans under normal circumstances.’
    • ‘Nearly all of the streams in urban areas contained insecticides commonly used on lawns, such as diazinon and malathion.’


1950s: from ( diethyl) mal(eate) (see maleic acid) + thio- + -on.