UK, 1808—to make one’s beliefs or intentions plain—from the former practice of nailing an ensign to the mast of a ship, after damage during battle resulted in the ship’s colours no longer being clearly displayed, which otherwise might have been interpreted as a signal of surrender
USA, 1917—a method of treating a drug addict by sudden and complete withdrawal of the drug, instead of by a gradual process—alludes to the goose pimples, resembling the skin of a cold turkey, that a person experiences as a side effect of the treatment
UK, 1824—thoroughly or perfectly right—‘trivet’: a metal tripod for a cooking pot or kettle to stand on—the phrase refers to a trivet’s always standing firm on its three feet
UK, 1860—very much, very intensely—‘billy-o’ occurs only in this phrase—it is apparently composed of ‘Billy’, pet form of the male forename ‘William’, and the suffix ‘-o’, used to form slang and colloquial nouns, adjectives and interjections
UK—‘the Beast from the East’ (2011): polar continental air mass, which brings wintry conditions—‘the Pest from the West’ (2012): mild air from the Atlantic, which brings strong winds and heavy rainfalls
UK, 2005—the perceived indiscriminate and excessive use by the authorities of anti-social behaviour orders—apparently coined by Álvaro Gil-Robles, the Council of Europe’s Commissioner for Human Rights—‘Asbo’: acronym from the initial letters of ‘anti-social behaviour order’
Australia, 1927—very drunk; sated with food—‘goog’, Australian-English slang for an egg, was perhaps formed on the sense of ‘gog’ in ‘goosgog’, denoting a gooseberry
USA, 1857—an exclamation expressing surprise or dismay—the motivation for the choice of the female forename ‘Betsy’ (variant of ‘Betty’, pet form of ‘Elizabeth’) is unknown