noun Chemistry.
  1. a brown liquid, C18H28O3S, insoluble in water, used as an insecticide synergist.
  2. any of the compounds with the radical =SO, as dimethyl sulfoxide, (CH3)2SO.

Origin of sulfoxide

First recorded in 1890–95; sulf- + oxide Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

sulfoxide in Medicine


  1. Any of various compounds that contain a sulfinyl group.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.