1. A material that hardens when heated and cannot be remolded
   - thermosetting resin

Type of: plastic

• unsought
• unsound
• unsoundable
• unsounded
• unsoundness
• unsourced
• unsoured
• unsown
• unspaced
• unsparing
• unsparingly
• unspeakable
• unspeakably
• unspecialised
• unspecialized
• unspecific
• unspecified
• unspectacular
• unspell
• unspent
• unspoiled
• unspoilt
• unspoken
• unspoken accusation
• unsporting