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
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
UK, 1763—extremely quickly or suddenly—in all probability, the male forename ‘Jack’, pet form of ‘John’, typifies an ordinary man, and the surname ‘Robinson’ is a generic personal name