1. Berserk (adj.) /bərˈsɜːrk/ — Meaning: Frenzied, violently out of control. — Origin: From Old Norse berserkr ("bear-shirt"), referring to Viking warriors who fought in a trance-like fury. — Example: "After the news, he went berserk and started yelling." 2. Quarantine (n.) /ˈkwɒr.ən.tiːn/ — Meaning: Isolation to prevent disease spread. — Origin: Italian quarantena ("40 days"), from the Venetian practice of isolating ships during the Black Death. — Example: "The travelers were placed in quarantine for two weeks." 3. Nightmare (n.) /ˈnaɪt.meər/ — Meaning: A frightening dream. — Origin: Old English mare (an evil spirit thought to suffocate sleepers), combined with "night." — Example: "She woke up sweating from a terrifying nightmare."