Definition of "vermiculite" []

• Any of a group of micaceous hydrated silicate minerals related to the chlorites and used in heat-expanded form as insulation and as a planting medium. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The name vermiculite was created from the Latin word for worm, vermiculus."
• "This year it is to be micro-plants, grown in vermiculite."
• "I need some stuff called vermiculite to condition the soil so that the roots grow well."