[ thur-moh-set-ing ]
/ ˈθɜr moʊˌsɛt ɪŋ /


pertaining to a type of plastic, as the urea resins, that sets when heated and cannot be remolded.

Nearby words

  1. thermoregulation,
  2. thermoremanent magnetization,
  3. thermos,
  4. thermoscope,
  5. thermosensitive,
  6. thermosiphon,
  7. thermosphere,
  8. thermostable,
  9. thermostat,
  10. thermostatics

Origin of thermosetting

First recorded in 1935–40; thermo- + setting Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for thermosetting


/ (ˌθɜːməʊˈsɛtɪŋ) /


(of a material, esp a synthetic plastic or resin) hardening permanently after one application of heat and pressure. Thermosetting plastics, such as phenol-formaldehyde, cannot be remouldedCompare thermoplastic
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

Science definitions for thermosetting


[ thûr′mō-sĕtĭng ]

Relating to a compound that softens when initially heated, but hardens permanently once it has cooled. Thermosetting materials are made of long-chain polymers that cross-link with each other after they have been heated, rendering the substance permanently hard. Compare thermoplastic.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.