Webster's Revised Unabridged Dictionary · 1913

Cacodyl

Cacodyl , noun

[Greek {not transcribed} ill-smelling (kako`s bad + {not transcribed} to smell) + -yl.]

(Chemistry) Alkarsin; a colorless, poisonous, arsenical liquid, As2(CH3)4, spontaneously inflammable and possessing an intensely disagreeable odor. It is the type of a series of compounds analogous to the nitrogen compounds called hydrazines.