The skin is the largest organ in the human body, covering a surface area of nearly 2 square meters. Skin covers a great deal of the English language, too, if we look to its many skin-related words, expressions, and idioms.
Let’s start with the word skin itself. In English, the word skin isn’t even comfortable in its own skin. Old English actually borrowed the word from the Scandinavian languages, like the early Scandinavian skinn. Skin originally referred to the hides of smaller animals, especially ones dressed and tanned, and was later applied to humans at least by the 14th century. The native term in Old English was hyd, which gives us hide, historically used of larger game.
There is record of thick-skinned in the English language by the middle of the 1600s, when the compound adjective described the literally thick rinds of fruits and vegetables. But it soon proved an apt metaphor. By the beginning of the 1500s, thick-skinned was characterizing persons as “dull” and “stupid,” later as “insensitive to criticism.” A derived term, a thickskin, was once used to tease dimwits.
Politics requires a thick skin, but, as we’ve recently seen, Democratic presumptive nominee Hillary Clinton has ribbed her Republican opponent, Donald Trump, as “thin-skinned.” While it’s a fresh attack on the campaign trail, the expression thin-skinned, like its counterpart thick-skinned, is surprisingly old: The Oxford English Dictionary (OED) documents it in its current “touchy” meaning as early as 1680.
4. UNDER ONE'S SKIN
Clinton’s jibe was intended to get under Donald Trump’s skin. This expression, to get under one’s skin, means to “irritate someone intensely” here. But a compelling movie, say, can also get under our skins when we continue to think about it long after it's over.
A different use of under the skin drives at something’s “true reality,” as opposed to its outer appearance. Rudyard Kipling popularized the expression in his late 19th-century poem “The Ladies.” In it, a philandering speaker draws his own conclusions about women no matter the color of their skin: “For the Colonel’s Lady an’ Judy O’Grady/ Are sisters under their skins!”
5. GET INTO ONE'S SKIN
We can get under one’s skin, but we can also get into one’s skin. This phrase, denoting deep empathy for another, far predates Luke Skywalker’s warmth-winning security in tauntauns. The OED attests it all the way back in 1372.
6. OUT OF ONE'S SKIN
English really itches to let you know exactly where we stand in relation to skin. We can jump or leap out of it when we’re excited. We can fly out of it when we get really angry. And we can play ourselves out of our skin if we do a great job at something.
7. NO SKIN OFF OUR …
We don’t just get in, under, and out of the skin. English also really likes to make sure its speakers don’t shed any skin. If we are not challenged by a particular situation or aren’t offended by some remark, it doesn’t even break the skin, so we say it’s no skin off our backs—or off our ears, noses, and even bugles, slang for “nose.”
8. SKIN OF ONE'S TEETH
Now, some people say a potentially face-losing situation is no skin off their teeth. This is a mixed metaphor, confusing expressions like no skin off the back with by the skin of my teeth, or a “narrow escape.” But what sort of monstrous teeth have skin?
This proverb is a literal translation of the Hebrew bĕʿōr šinnāi, used in the Book of Job. Scholars widely dispute the translation, though. The OED points to some other notable translations: The Latin Vulgate renders the passage as “only my lips are left around my teeth” and the Greek Septuagint as “my bones are held in my teeth.”
9. GIVE ME SOME SKIN
We’re not always trying to save our skins. We also like to give it away. Give me some skin originated as early as the 1940s as African American slang for shaking hands or related nonverbal exchanges.
10. SKIN IN THE GAME
Seventies financial slang, meanwhile, put skin in the game, “to have a stake in something,” especially a monetary investment. This skin may harken back to the risk-taking suggested by save one’s skin.
Some games do feature skins, in a manner of speaking. In a scrimmage or pickup match, teams may differentiate their sides in a shirts and skins game. The usage is evidenced by the 1930s, around the same time we see skins in what golf now calls a skins game, in which the winner of each hole is awarded money, or skins. The term might be related to some other skin-related slang for money: frogskin and toadskin.
11. AND 12. FROGSKIN AND TOADSKIN
In the 19th century, Americans nicknamed five-cent stamps toadskins. Historically, such stamps often had a greenish hue, much like the country’s current paper money. Also as inspired by the amphibians’ color, toadskins, and a related form, frogskins, later referred to one-dollar bills. Yet earlier, British criminal slang called purses and wallets skins, perhaps because they were made from leather.
A skinflint is a “mean and miserly person,” so said because such a money-grubbing individual would skin a flint—trying to strip a small chunk of the hard stone—in the name of profit. This originally British expression dates to the 17th century. An American variant is to skin a flea for its hide and tallow.
14. A GOOD SKIN
Some dialects of Irish English call a person a good skin. This is not a comment on the health of the person’s epidermis; skin is a general term for a “person” or “lad,” or “guy” or “dude” across the pond. To some Dubliners, a skinnymalink is a lanky fellow. The origin is unknown, but some students of Irish English think it may ultimately be a corruption of skin and bones, itself an old term for an emaciated individual.
The OED gives the first attestation of skinny—as we think of (or aspire to) this adjective today—to Shakespeare’s Banquo addressing the witches in Macbeth: “You seem to understand me,/By each at once her choppy finger laying/ Upon her skinny lips.” Earlier, skinny was more literal: “covered by skin,” as the dictionary glosses. The OED finds an older but rarer usage: “ioynge in skinnes” or “gloriouse skinny,” a way to comment on one’s attractiveness by their youthful integument.
But we all know beauty is only skin-deep. The OED cites this proverb in a poem by Sir Thomas Overbury written in the 1610s: “All the carnall Beautie of my wife, is but skinne-deepe.”
Think venti skinny pumpkin-spice lattes are trendy? A New York Times advertisement marketed skinny, or “low-calorie,” shakes, malteds, parfaits, and hot chocolates in 1969. Suppose your skinny jeans are hip? A heading in a 1915 edition of The Waterloo Times-Tribune read: “Skinny clothes in vogue this year.” The article continued: “The correctly dressed man for 1915 will display a ‘quick fit’. Fashion has decreed that the tight fitting clothes of the past year shall become more so.”
16. THE SKINNY
What’s the skinny? Today, this sounds like a quaint way of saying “What’s up?” But in a casual conversation in the early 20th century, one would want to get the skinny on some inside scoop of a newsy or gossipy bit of information. The origin is obscure, but underlying this colloquial usage seems to be a notion of the “naked truth.”
Speaking of nakedness, or being to the skin, we’ve been skinny-dipping since at least the mid-20th-century in the United States, stripping right down to nothing but our birthday suits before plunging into water.
18. SHOWING SOME SKIN
Still speaking of nakedness, skin has its more adult associations, too. A skin-flick is slang for a “porno.” In Japan, skin ladies sold condoms, or skins, from door to door.
19. NEW SKINS
Socially, we are still striving to transcend the arbitrary differences of skin color. Mortally, we are still trying to defy age with the cosmetics of skin food. And linguistically, we are overcoming the limits of physical reality with digital skins. Gamers can buy or earn new skins: These alter or enhance the appearance of a game by, say, changing the appearance of a character or adding to its gear. Skins can also refer to stylized cases one can put on a cellular phone, computer, or gaming console.