diquat

[dahy-kwot]
noun
  1. a yellow crystalline substance, C12H12Br2N2, used as a selective postemergence herbicide to control weeds on noncrop land and for aquatic weed control.

Origin of diquat

First recorded in 1955–60; di-1 + quat(ernary)
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018