a crystalline insoluble substance, consisting of a chlorinated derivative of naphthalene: a contact insecticide the use of which is now restricted as it accumulates in the tissues of animals. Formula: C12H8OCl6
Word origin
C20: from Diel(s-Al)d(e)r (reaction) + -in
dieldrin in American English
(ˈdildrɪn)
US
noun
a highly toxic, long-lasting insecticide, C12H8OCl6, restricted by law to nonagricultural use