Why salt?
The most common road and sidewalk de-icer in use today is rock salt (aka halite, aka sodium chloride). While there are more effective de-icers, NaCl’s predominance is because it’s cheap, which is very relevant at the scale street de-icer is used. It has two primary mechanisms of action: one, the uneven surface increases traction; and two, the freezing point of salt water is -17C (0F) rather than 0C (32F), so at temperatures between -17C and 0C, less ice actually forms.
Salt’s cheapness is extra funny from a historical perspective. Salt was an essential trade good whose importance is clear from the salt mines of Salzburg (literally, “salt castle”) to the Classical Latin noun salarium (literally, “saltiness”), the ancestor of English salary. It’s not just that you will literally die if you don’t eat enough salt; it’s also an important way to preserve food in the millennia before refrigeration.
Salt deficiency’s mechanism of action of causing death turns out to be the same as what you die from if you drink too much water, hyponatremia. Water is the substance with the highest known LD50: an average person has a 50% chance of dying after drinking about 7 liters (2 gallons) of water in one sitting. The least deadly substance known to man is somehow still the cause of most deaths by drowning.
barbecue
The cuisine barbecue first appears in American English as a loanword from American Spanish barbacoa, meaning “barbecue”, around 1700. Barbacoa, reborrowed into English in 1953 as barbacoa referring specifically to Mexican cuisine, was itself a loanword, but its history remains unclear. The consensus is that it’s a borrowing from Taíno barbakoa, meaning “framework of sticks”, but the word’s popularization seems to originate in Mexico, which did not have many Taíno (or other Arawakan language) speakers. The OED instead attributes it to Haitian barbacòa (through Taíno), but there’s also speculation it’s from Mayan Baalbak’Kaab instead.
In any case, the slow cooking of leaf-wrapped meat in an oven constructed in a hole in the ground is widespread among indigenous Mesoamerican cultures. In the Yucatan, the Mayan word for the oven is píib, and the resulting cooked meat is called pibil.
Today barbecue mostly refers to regional US cuisines. The cookout event barbecue is from 1733 (George Washington writes about attending a Virginia barbicue in 1769). The grill barbecue is from 1931. Of the four major regional US traditions, Carolina barbecue goes back to at least 1760, Texas barbecue is clearly distinct by 1860, Kansas City barbecue splits off in 1908, and Memphis barbecue is well established by 1950. The clipping Bar-B-Q is from 1926, further abbreviated to BBQ by 1938. Heinz began selling barbecue sauce nationally in 1940. Barbie originates from Australian slang in 1976.
normal
The value judgment normal has an extremely normal history. It originates with PIE ǵneh₃-, meaning “to know”, incidentally also the ancestor of the English word know. 3000 years ago, one of its descendants was Ancient Greek γνώμων (gnṓmōn), meaning “examiner” or “carpenter’s square”, the tool you use to measure right angles. It also referred to the thing that sticks up at a right angle in the middle of a sundial due to its similar shape, from where we borrowed English gnomon.
The word was borrowed into Classical Latin maybe 2200 years ago as norma, meaning only “carpenter’s square”. Over the next thousand years, the meaning became generalized to “rule” or “pattern”, from where we borrowed English norm. A derived word, Classical Latin normālis, meant “made according to a carpenter’s square”. This is the sense we borrowed normal from around 1704, then meaning “at right angles” or “perpendicular to”. Normal still refers to right angles in some modern technical usages like normal vector (often shortened to normals, in the graphics sense).
By the 1840s, influenced by norm, normal started typically meaning “according to a rule or pattern” instead. With the help of new fields of ergonomics and standards, by 1890 the word’s meaning had generalized to referring to usual or common values, based on observed patterns. Within a few decades, its usage had changed to almost always mean “typical state or condition”.
Abnormal is attested as early as 1817. The normal distribution was named by Carl Gauss in 1823 based on the “perpendicular” meaning, which is why we interchangeably say Gaussian distribution (or Gaussian blur). In 1835, we calqued normal school from French école normale, meaning “teacher’s college” by way of teaching the teachers to enforce the norms. Most US schools founded as normal schools are now public colleges, including the Normal University founded in 1857 in Illinois, now Illinois State University but located in the eponymous city of Normal, Illinois. Paranormal shows up in 1905. Normie is from 1950. Normcore first appears around 2008. Having a normal one starts becoming popular around 2022.
syllabus
The academic summary syllabus is first used as an English word in 1653, borrowed from Late Latin syllabus, meaning “list”. Syllabus comes from a misprint in a 1470s copy of a Cicero work, duplicated faithfully for centuries. The Latin word was originally sittybas, a borrowing from Ancient Greek σιττύβας (sittúbas), meaning “parchment label”. Σιττύβας were leather slips placed on the ends of scrolls in Greek libraries with a table of contents so that scribes could more quickly find the right scrolls.
pajamas
The outfit pajamas first appears in English as a loanword from Urdu, in a British newsletter about South Asia in 1800. In Urdu, it’s written پاجام (pājāma), or पाजामा (pājāmā) in Hindi, and has the same meaning. Those descend from Classical Persian پَاجَامَه (pājāma), meaning “pants”, through the Islamic Mughal Empire’s conquest of northern India. The Persian word comes from Persian roots پَا (pā), meaning “leg”; and جَامَه (jāma), meaning “clothing”. A much more prosiac origin than pants. Finally, pā descends from PIE ped-, meaning “foot”. Deep down, it’s all from the same root found in pedal, podium, or foot.
UK and Commonwealth English instead prefer the spelling pyjamas, based on the alternate Hindi spelling पैजामा (paijāmā), based on the alternate Persian spelling پَای (pāy). The British fashion of men using pajamas as nightwear is more recent, dating to 1870. Before that, the customary sleepwear was a nightshirt, or a nightgown for women. The abbreviation PJs is from 1930, while jammies is first seen in 1928. Pajama party as a subtype of slumber party is from the 1950s. Pajamas were briefly high fashion outerwear in the late 1960s and 1970s, but did not become common street clothes until their 2018 revival. The Australian children’s TV show “Bananas in Pyjamas” began airing in 1992.