1. (of metal or glass) not annealed and consequently easily cracked or fractured
   - brittle

See also: unhardened, untempered

• underage
• underarm
• underbelly
• underbid
• underbodice
• underbody
• underboss
• underbred
• underbrush
• undercarriage
• undercharge
• underclass
• underclassman
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• underclothes
• underclothing
• undercoat
• undercoated
• undercook
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• undercover agent
• undercover operation
• undercover work
• undercroft
• undercurrent