IPA: /ˈθɜːrməˌsɛtɪŋ/
KK: /ˈθɜrməˌsɛtɪŋ/
A type of material that becomes permanently hard when heated, often used in making certain plastics and resins.
The thermosetting plastic is used in many household items because it is very durable.
Thermosetting is formed from "thermo-" (from Greek "thermos", meaning hot or heat) and "setting" (from Old English "settan", meaning to place or fix). The word describes a type of plastic that sets or hardens when heated, thus becoming fixed in shape.
Think of 'heat' ('thermo-') causing a material to 'set' or 'fix' in place, which is what thermosetting materials do.
No commonly confused words.