noun Chemistry.

a toxic herbicide, C12H14N2⋅2CH3SO4, applied to food and flower crops and to highway borders as a defoliant and weed-killer.

Origin of paraquat

1960–65; para-1 + quat(ernary), in reference to the bond between the two pyridyl groups, which is in the para position with respect to their quaternary nitrogen atoms Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for paraquat

pesticide, fungicide, defoliant, insecticide, weedkiller, DDT

British Dictionary definitions for paraquat



trademark a yellow extremely poisonous soluble solid used in solution as a weedkiller
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for paraquat

quick-acting herbicide, 1961, from para- (1) + first element in quaternary. So called in reference to its chemical configuration.

Online Etymology Dictionary, © 2010 Douglas Harper

paraquat in Medicine




A colorless compound or related yellow compound used as a herbicide.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

paraquat in Science



A toxic compound used as a herbicide, especially in its colorless, dichloride form (C12H14Cl2N2) or in its yellow, bismethyl sulfate form (C14H20N2O8S2). Paraquat is used primarily to control grass and weeds. Its use in the United States is restricted because of its high level of toxicity.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.