Don’t Quit, It’s Legit
If an authentic thing is said to pass an “acid test,” it is because real gold also had to pass one in the gold rush days. Gold’s non-reactivity to nitric acid distinguished it from lookalike iron pyrite, aka “fool’s gold.”
“The proof is in the pudding” derives from “the proof of the pudding,” which shortened “the proof of the pudding is in the eating.” This expression just meant you have to try food to learn whether its good. When the term began, however, “pudding” was a dish made of animal intestines stuffed with meat and other foods.
“Bona fide” also conveys that something is authentic, and is Latin for “in good faith.”
There many possible origins of the term “The Real McCoy,” to indicate an authentic. It could have first referred to the automatic train engine oiling system patented by inventor Elijah McCoy in 1872, as opposed to an inferior knock-off device. It could be a mispronunciation of the advertising slogan “A drappie (drop) o’ the Real MacKay” used in 1856 by the G. MacKay and Co., Ltd. whiskey distillery. It could come from 1930s radio host George Brainwood McCoy, who would sign off by saying “This is Sergeant George (The Real) McCoy folding his microphone and silently stealing away.” A dispute over the rightful leader of the Scots Clan McCoy could also be the origin, and there are even more possibilities.
Someone who is “dyed in the wool” is considered thoroughly subscribed to an opinion or belief. This term originates from the practice of dying wool when it is raw and before it is spun, meaning the color runs throughout the fiber and not just near the surface, and therefore lasts longer.
If a person or transaction is “on the level,” this indicates honesty and fairness. This appears to be a Freemasonry-inspired term, since level surfaces and buildings are more solid and sound, a level is a mason’s tool, and, like with a “level playing field,” equality for all parties is implied.
“Honest to goodness,” the description of something simple and genuine, is a variation of “honest to God,” the last word’s swap being a safety against blasphemy.