1. The univalent arsenic group (CH3)2As.
2. A poisonous oil, As2(CH3)4, with an obnoxious garlicky odor.
[Greek kakōdēs, bad-smelling (kakos, bad; see kakka- in the Appendix of Indo-European roots + -ōdēs, -smelling, from ozein, ōd-, to smell) + -YL.]
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